1: a mythical Greek hero of the Iliad; a foremost Greek warrior at the siege of Troy; when he was a baby his mother tried to make him immortal by bathing him in a magical river but the heel by which s...

1: a large tendon that runs from the heel to the calf [syn: {tendon of Achilles}]

1: a seemingly small but actual mortal weakness

1: any plant of the genus Achimenes having showy bell-shaped flowers that resemble gloxinias [syn: {hot water plant}]

1: causing a dull and steady pain; "my aching head"; "her old achy joints" [syn: {achy}] n : a dull persistent (usually moderately intense) pain [syn: {ache}]

1: canna grown especially for its edible rootstock from which arrowroot starch is obtained [syn: {indian shot}, {arrowroot}, {Canna indica}, {Canna edulis}]

1: not having a floral envelope or perianth [ant: {chlamydeous}]

1: an abnormal deficiency or absence of free hydrochloric acid in the gastric juice; often associated with severe anemias and cancer of the stomach

1: lacking hydrochloric acid

1: Indonesian statesman who obtained the independence of Indonesia from the Netherlands in 1949 and served as president until ousted by Suharto in a coup d'etat (1901-1970) [syn: {Sukarno}]

1: a genus of Labridae [syn: {genus Achoerodus}]

1: found around the Great Barrier Reef [syn: {pigfish}, {giant pigfish}]

1: a condition in which little or no bile is secreted or the flow of bile into the digestive tract is obstructed [syn: {cholestasis}]

1: a member of the North American Indian people of the Pit river valley in northern California 2: the Shastan language spoken by the Achomawi people

1: a stony meteor lacking chondrules

1: of or related to an achondrite 2: not having a granular structure [ant: {chondritic}]

1: an inherited skeletal disorder beginning before birth; cartilage is converted to bone resulting in dwarfism [syn: {achondroplasty}, {osteosclerosis congenita}, {chondrodystrophy}]

1: of or relating to achondroplasia

1: an inherited skeletal disorder beginning before birth; cartilage is converted to bone resulting in dwarfism [syn: {achondroplasia}, {osteosclerosis congenita}, {chondrodystrophy}]

1: tropical trees having papery leaves and large fruit [syn: {genus Achras}]

1: large tropical American evergreen yielding chicle gum and edible fruit; sometimes placed in genus Achras [syn: {sapodilla}, {sapodilla tree}, {Manilkara zapota}]

1: unnatural lack of color in the skin (as from bruising or sickness or emotional distress) [syn: {lividness}, {lividity}, {luridness}, {paleness}, {pallidness}, {pallor}, {wanness}]

1: being of the achromatic color of maximum lightness; having little or no hue owing to reflection of almost all incident light; "as white as fresh snow"; "a bride's white dress" [syn: {white}] [ant: ...

1: a color lacking hue; white or gray or black [syn: {achromatic colour}] [ant: {chromatic color}]

1: a color lacking hue; white or gray or black [syn: {achromatic color}] [ant: {chromatic color}]

1: a compound lens system that forms an image free from chromatic aberration

1: vision using the rods

1: the part of a cell nucleus that is relatively uncolored by stains or dyes

1: (of substance of a cell nucleus) not readily colored by stains [ant: {chromatinic}]

1: remove color from; "achromatize the lenses" [syn: {achromatize}]

1: the visual property of being without color [syn: {colorlessness}, {colourlessness}] [ant: {color}]

1: remove color from; "achromatize the lenses" [syn: {achromatise}]

1: having little or inadequate color

1: an absence of normal pigmentation especially in the skin (as in albinism) or in red blood cells

1: having no color [syn: {achromous}]

1: having no color [syn: {achromic}]

1: an antibiotic (trade name Achromycin) derived from microorganisms of the genus Streptomyces and used broadly to treat infections [syn: {tetracycline}]

1: causing a dull and steady pain; "my aching head"; "her old achy joints" [syn: {aching}]

1: absence of gastric juices (partial or complete) [syn: {achylia gastrica}]

1: absence of gastric juices (partial or complete) [syn: {achylia}]

{aciculum} [also: {aciculae} (pl)]

{acicula}

1: narrow and long and pointed; as pine leaves [syn: {acerate}, {acerose}, {needle-shaped}]

1: related to plants or animals or crystals having aciculae or needle-like parts

1: harsh or corrosive in tone; "an acerbic tone piercing otherwise flowery prose"; "a barrage of acid comments"; "her acrid remarks make her many enemies"; "bitter words"; "blistering criticism"; "cau...

1: organic compounds that react with water to form an acid [syn: {acyl anhydrides}]

1: dye in which the chromophore is part of a negative ion

1: organic compounds containing the group -COX where X is a halogen atom [syn: {acyl halide}]

1: someone who takes LSD

1: a hydrogen atom in an acid that forms a positive ion when the acid dissociates [syn: {acidic hydrogen}]

1: rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water [syn: {acid rain}]

1: rain containing acids that form in the atmosphere when industrial gas emissions (especially sulfur dioxide and nitrogen oxides) combine with water [syn: {acid precipitation}]

1: a musical style that emerged in the mid-1960s; rock music inspired by or related to drug-induced experience [syn: {psychedelic rock}]

1: a rigorous or crucial appraisal

1: (chemistry) the amount of free acid present in fat as measured by the milligrams of potassium hydroxide needed to neutralize it; "as the glycerides in fat slowly decompose the acid value increases"

1: (physiology) the normal equilibrium between acids and alkalis in the body; "with a normal acid-base balance in the body the blood is slightly alkaline" [syn: {acid-base equilibrium}]

1: (physiology) the normal equilibrium between acids and alkalis in the body; "with a normal acid-base balance in the body the blood is slightly alkaline" [syn: {acid-base balance}]

1: an indicator that changes color on going from acidic to basic solutions

1: not easily decolorized by acid solutions; pertains to micro-organisms (especially the tubercle bacillus that causes tuberculosis)

1: yielding an acid in aqueous solution

1: thriving in a relatively acidic environment (especially of plants requiring a pH well below 7) [ant: {alkaline-loving}]

1: wash with acid so as to achieve a bleached look; "acid-wash blue jeans"

1: a blood disorder characterized by an increased concentration of hydrogen ions in the blood (which falls below 7 on the pH scale)

1: being or containing an acid; of a solution having an excess of hydrogen atoms (having a pH of less than 7) [ant: {alkaline}, {amphoteric}] 2: tasting sour like acid [syn: {acidulent}, {acidulous}]

1: a hydrogen atom in an acid that forms a positive ion when the acid dissociates [syn: {acid hydrogen}]

1: the process of becoming acid or being converted into an acid

{acidify}

1: make sour or more sour [syn: {sour}, {acidulate}, {acetify}] [ant: {sweeten}] 2: turn acidic; "the solution acetified" [syn: {acetify}] [ant: {alkalize}] [also: {acidified}]

1: involving or related to acidimetry

1: volumetric analysis using standard solutions of acids to measure the amount of a base present

1: the property of being acidic [syn: {sourness}, {sour}] 2: the taste experience when something acidic is taken into the mouth [syn: {acidulousness}] 3: pH values below 7 [ant: {alkalinity}]

1: an organism that thrives in a relatively acid environment [syn: {acidophile}]

1: an organism that thrives in a relatively acid environment [syn: {acidophil}]

1: especially of some bacteria; growing well in an acid medium [syn: {acidophilous}, {aciduric}]

1: especially of some bacteria; growing well in an acid medium [syn: {acidophilic}, {aciduric}]

1: milk fermented by bacteria; used to treat gastrointestinal disorders

1: abnormally high acidity (excess hydrogen-ion concentration) of the blood and other body tissues

1: having or being characterized by acidosis

1: make sour or more sour [syn: {sour}, {acidify}, {acetify}] [ant: {sweeten}]

1: made slightly acid

1: tasting sour like acid [syn: {acidic}, {acidulous}]

1: tasting sour like acid [syn: {acidic}, {acidulent}]

1: the taste experience when something acidic is taken into the mouth [syn: {acidity}]

1: especially of some bacteria; growing well in an acid medium [syn: {acidophilic}, {acidophilous}]

1: pertaining to one of the small sacs (as in a compound gland) [syn: {acinous}, {acinose}, {acinic}] 2: pertaining to the individual parts making up an aggregate fruit like a blackberry

{acinus}

1: pertaining to one of the small sacs (as in a compound gland) [syn: {acinar}, {acinous}, {acinose}]

1: cheetahs [syn: {genus Acinonyx}]

1: long-legged spotted cat of Africa and southwestern Asia having nonretractile claws; the swiftest mammal; can be trained to run down game [syn: {cheetah}, {chetah}]

1: plants closely allied to the genera Satureja and Calamintha [syn: {genus Acinos}]

1: fragrant European mint having clusters of small violet-and-white flowers; naturalized especially in eastern North America [syn: {basil thyme}, {basil balm}, {mother of thyme}, {Satureja acinos}]

1: pertaining to one of the small sacs (as in a compound gland) [syn: {acinar}, {acinous}, {acinic}]

1: pertaining to one of the small sacs (as in a compound gland) [syn: {acinar}, {acinose}, {acinic}]

1: one of the small drupes making up an aggregate or multiple fruit like a blackberry 2: one of the small sacs or saclike dilations in a compound gland [also: {acini} (pl)]

1: type genus of the Acipenseridae: sturgeons [syn: {genus Acipenser}]

1: valuable source of caviar and isinglass; found in Black and Caspian seas [syn: {beluga}, {hausen}, {white sturgeon}]

1: food and game fish of marine and fresh waters of northwestern coast of North America [syn: {Pacific sturgeon}, {white sturgeon}, {Sacramento sturgeon}]

1: sturgeons [syn: {family Acipenseridae}]

1: artillery designed to shoot upward at airplanes [syn: {antiaircraft}, {antiaircraft gun}, {flak}, {flack}, {pom-pom}, {ack-ack gun}]

1: artillery designed to shoot upward at airplanes [syn: {antiaircraft}, {antiaircraft gun}, {flak}, {flack}, {pom-pom}, {ack-ack}]

1: red pear-shaped tropical fruit with poisonous seeds; flesh is poisonous when unripe or overripe [syn: {akee}]

1: declare to be true or admit the existence or reality or truth of; "He admitted his errors"; "She acknowledged that she might have forgotten" [syn: {admit}] [ant: {deny}] 2: report the receipt of; "...

1: capable of being acknowledged

1: recognized or made known or admitted; "the acknowledged leader of the community"; "a woman of acknowledged accomplishments"; "his acknowledged error" [ant: {unacknowledged}] 2: generally accepted

1: the state or quality of being recognized or acknowledged; "the partners were delighted with the recognition of their work"; "she seems to avoid much in the way of recognition or acknowledgement of ...

1: the state or quality of being recognized or acknowledged; "the partners were delighted with the recognition of their work"; "she seems to avoid much in the way of recognition or acknowledgement of ...

1: a major strategic headquarters of NATO located in the United States; is under the authority of the North Atlantic Council [syn: {Allied Command Atlantic}]

1: an imaginary line paralleling the equator where a magnetic needle has no dip [syn: {magnetic equator}]

1: the highest level or degree attainable; "his landscapes were deemed the acme of beauty"; "the artist's gifts are at their acme"; "at the height of her career"; "the peak of perfection"; "summer was...

1: an inflammatory disease involving the sebaceous glands of the skin; characterized by papules or pustules or comedones

1: a skin disease of adults (more often women) in which blood vessels of the face enlarge resulting in a flushed appearance [syn: {rosacea}]

1: the most common form of acne; usually affects people from puberty to young adulthood

1: (of complexion) blemished by imperfections of the skin [syn: {pimpled}, {pimply}, {pustulate}]

1: resembling acne

1: a subclass of Sporozoa [syn: {subclass Acnidosporidia}]

1: small genus of trees and shrubs containing strongly toxic cardiac glycosides; Arabia to Africa [syn: {genus Acocanthera}, {Acokanthera}, {genus Acokanthera}]

1: medium-sized shrubby tree of South Africa having thick leathery evergreen leaves and white or pink flowers and globose usually two-seeded purplish black fruits [syn: {winter sweet}, {poison arrow p...

1: evergreen shrub or tree of South Africa [syn: {bushman's poison}, {ordeal tree}, {Acocanthera venenata}]

1: medium-sized shrubby tree of South Africa having thick leathery evergreen leaves and white or pink flowers and globose usually two-seeded purplish black fruits [syn: {winter sweet}, {poison arrow p...

1: evergreen shrub or tree of South Africa [syn: {bushman's poison}, {ordeal tree}, {Acocanthera oppositifolia}]