apportionment, n. allotment, partition.

appreciable, a. perceptible, discernible.  Antonym:  inappreciable.

appreciate, v. value, esteem, prize.

appreciation, n. valuation, estimation, esteem.  Antonyms:  depreciation, inappreciation.

apprehend, v. arrest, seize; understand, recognize, consider believe; anticipate, dread, fear.

apprehension, n. seizure; arrest; opinion, conception, belief, notion; understanding; fear, dread, anxiety, solicitude, alarm.

apprehensive, a. discerning, apt; fearful, anxious, worried.

approachable, a. accessible.  Antonym:  unapproachable.

appropriate, a. fitting, proper, applicable, apposite, pertinent, fit.  Antonyms:  See inappropriate.

approval, n. approbation, sanction, commendation, liking, indorsement.  Antonyms:  See disapproval.

approve, v. commend, sanction, countenance, favor, like.

apron, n. pinafore, tier; boot.

apt, a. fit, relevant, appropriate, germane, applicable, felicitous, pertinent, apropos; likely, liable; clever, intelligent, bright, deft.  Antonyms:  See inapt.

aptitude, n. proneness, propensity, leaning, proclivity, inclination.  Antonym:  inaptitude.

aptness, n. appropriateness, pertinence; intelligence, cleverness.

arbitrary, a. tyrannical, absolute, imperious, unrestrained, dictatorial.

arbitrator, n. arbiter, umpire, judge, referee.

arbor, n. bower, pergola, trellis.

arch, a. greatest, chief; cunning, roguish, mischievous, sportive.

arch, v. vault, concamerate.—­n. concameration, fornication.

archaeologist, n. antiquary, antiquarian, paleologist.

archaeology, n. paleology.

archbishop, n. primate, metropolitan.

arched, a. vaulted, camerated, forniciform, fornicated.

archery, n.  Associated Word:  toxophilite.

archives, n. pl. public records, registers, muniments.

ardent, a. zealous, passionate, fervent, warm, enthusiastic, sanguine, vehement, impassioned; spirituous, alcoholic; fiery, hot, burning, flagrant, intense.

ardor, n. eagerness, zeal, heartiness, impetuosity, fervor, vehemence, empressement, intensity, warmth.  Antonyms:  indifference, apathy.

arduous, a. onerous, difficult, laborious, wearisome.

arena, n. amphitheater, ring, field.

arguable, a. debatable, disputable, moot, contestable.

argue, v. reason, plead, remonstrate, expostulate; contend, dispute, controvert, moot, discuss; prove, evince, betoken, indicate, imply, denote.

arguer n. reasoner, disputant, debater, controversialist.

argument, n. reasoning, controversy, argumentation, discussion, debate, dispute, disputation, polemic.

argumentative, a. ratiocinative; disputatious, polemical, controversial, dialectical.