| aorist | n. | simple past tense in Ancient Greek, with no further limitations or restrictions; undefined | ||
| aoudad | n. | Barbary sheep | ||
| aperient | adj. | laxative | ||
| aphelion | n. | point at which a body in solar orbit is farthest from the sun | ||
| apical | adj. | of or related to an apex | ||
| aplanatic | adj. | (of a lens) free of spherical and comatic aberration | ||
| apocope | n. | loss, omission, or suppression of final letter, syllable, or sound of a word | ||
| apodictic | adj. | incontestable because demonstrable | ||
| apodosis | n. | consequent in a conditional sentence | rhetoric | |
| apolaustic | adj. | dedicated to pleasure or enjoyment | ||
| apologue | n. | allegorical tale with a moral lesson | ||
| apolune | n. | highest point of an orbit around a moon | ||
| apophallation | n. | the biting off of the penis | ||
| apophasis | n. | rhetorical figure in which speaker brings up the very subject he or she pretends to deny | ||
| apophenia | n. | tendency to incorrectly perceive connections between unrelated things | ||
| aposiopesis | n. | rhetorical device in which the speaker suddenly stops, as if unable or unwilling to continue | ||
| apostrophe | n. | rhetorical figure wherein the speaker digresses and pointedly addresses some person or personified object | ||
| apotelesm | n. | the casting of a horoscope | ||
| apothegm | n. | terse maxim; sententious saying | ||
| apotheosis | n. | deification, elevation to the rank of a god | ||
| apotropaic | adj. | intended to ward off evil | ||
| appanage | n. | customary accompaniment | ||
| appetence | n. | longing, desire; instinctive inclination | ||
| apple scrumping | n. | to steal apples from an orchard, to take fallen apples from another’s grounds | ||
| appoggiatura | n. | grace-note prepended to essential tone of a melody | ||
| apposite | adj. | well put, suitable | ||
| appositive | n. | word or phrase used in apposition (grammar) | ||
| appulse | n. | forceful movement towards or against; apparent nearness between astronomical objects, conjunction | ||
| apricity | n. | light or heat of the sun | obsolete | |
| apteryx | n. | kiwi | ||
| aptotic | adj. | uninflected | ||
| aquamanile | n. | medieval pitcher, often shaped like an animal | ||
| arabesque | adj. | fanciful decoration or ornament combining figures, flora, and fauna in flowing lines; fantastic, oddly mixed | ||
| arbalest | n. | crossbow using metal bow to shoot bolts or stones | ||
| architrave | n. | primary beam or lintel lying atop a series of columns, the lowest section of a classical entablature (below the frieze and cornice), epistyle; frame with mouldings around door or window | ||
| arctics | n. | waterproof overshoes appropriate for cold weather | ||
| arctophile | n. | lover or collector of teddy bears | ||
| areology | n. | study of the planet Mars | ||
| argal | conj. | therefore (used facetiously to suggest clumsy reasoning) | ||
| argand | n. | argand lamp, improved oil lamp developed in 18th Century by Aimé Argand | ||
| argosy | n. | large merchant ship; merchant fleet; large supply | ||
| argy-bargy | n. | vigorous verbal dispute, loud wrangling | ||
| Arimaspian | n. | legendary single-eyed peoples of northern Scythia | ||
| aristarchian | adj. | very or overly critical | ||
| armamentarium | n. | materials and methods for performing given duties | ||
| armscye | n. | armhole in a garment | ||
| arnophilia | n. | bestial sexual congress between men and sheep | ||
| aroint | v. | begone, get hence | archaic | |
| arpent | n. | old French unit of area roughly equal to an acre, still used in Francophone America | ||
| arrack | n. | liquor made from fermented sap of palm or cane or fermented rice, typically distilled in India and Southeast Asia |
