mid-14c., "one who forsakes his religion or faith," from Old French apostat and directly from Late Latin apostata (which form also was used in Middle English), from Greek apostasia, apostasis "defection, desertion, rebellion," from apostanai "to defect," literally "to stand off," from apo "off, away from" (see apo-) + stanai, aorist of histanai "to set, place," literally "cause to stand" (from PIE root *sta- "to stand, make or be firm").

The word was used from mid-14c. in non-religious situations, "one who has forsaken the party, opinion, etc., to which he previously adhered."

mid-14c., "shopkeeper," especially "pharmacist; one who stores, compounds, and sells medicaments," from Old French apotecaire (13c., Modern French apothicaire), from Late Latin apothecarius "storekeeper," from Latin apotheca "storehouse," from Greek apothēkē "barn, storehouse," literally "a place where things are put away," from apo "away" (see apo-) + thēkē "receptacle" (from a suffixed form of PIE root *dhe- "to set, put").

The same Latin word produced French boutique, Spanish bodega, German Apotheke. Cognate compounds produced Sanskrit apadha- "concealment," Old Persian apadana- "palace."

Drugs and herbs being among the chief items of non-perishable goods, the meaning narrowed 17c. to "druggist" (the Apothecaries' Company of London separated from the Grocers' in 1617). Apothecaries were notorious for "the assumed gravity and affectation of knowledge generally put on by the gentlemen of this profession, who are commonly as superficial in their learning as they are pedantic in their language" [Francis Grose, "A Classical Dictionary of the Vulgar Tongue," 1796]. Hence, Apothecary's Latin, barbarously mangled, also known as Dog Latin.

mid-14c., appropren, "acquire possession or control, to appropriate, take possession of," from Old French apropriier "annex; make fit or suitable" (12c., Modern French appropre), from Late Latin appropriare "make one's own" (see appropriate (v.)).

mid-14c., "inclined, disposed;" late 14c., "suited, fitted, adapted, possessing the necessary qualities for the purpose," from Old French ate "fitting, suitable, appropriate" (13c., Modern French apte), or directly from Latin aptus "fit, suited, proper, appropriate," adjectival use of past participle of *apere "to attach, join, tie to." This is reconstructed to be from PIE root *ap- (1) "to grasp, take, reach" (source also of Sanskrit apnoti "he reaches," Latin apisci "to reach after, attain," Hittite epmi "I seize"). The elliptical sense of "becoming, appropriate" is from 1560s.

mid-14c., "hollow place under the shoulder," from arm (n.1) + pit (n.1). Arm-hole (early 14c.) was used in this sense but was obsolete by 18c. Another Middle English word was asselle (early 15c.), from Old French asselle, from Latin axilla. The colloquial phrase armpit of the nation for any locale regarded as ugly and disgusting was in use by 1965.

mid-14c., "marshal (troops), arrange (an army for battle);" late 14c., "put (things) in order, arrange; get (something) ready, prepare; equip, fit out, put clothing on; adorn, decorate," from Old French areyer, earlier areer "to put in order," from Vulgar Latin *ar-redare "put in order" (source also of Italian arredare), from Latin ad "to" (see ad-) + *redum, from Frankish *ræd- "ready" or some cognate Germanic source, from Proto-Germanic *raidjan "to place in order" (source also of Gothic garadis, Old English geræde "ready;" see ready (adj.)). Related: Arrayed; arraying.

mid-14c., "order or position of things, arrangement, sequence," from Anglo-French arrai, Old French aroi, arroi (12c.), from areer "to put in order" (see array (v.)). From late 14c. as "rank or line of soldiers; troops drawn up in battle formation," also "equipment, furnishings, gear; splendid furnishings, grandeur, magnificence." The meaning "an orderly assemblage" is from 1814.

mid-14c., artetyk, "pertaining to arthritis," also as a noun, from Old French artetique (12c., Modern French arthritique), corresponding to Latin arthriticus, from Greek arthritikos, from arthritis (see arthritis). The spelling gradually was restored to Latin form in 17c.

mid-14c., ascrive, "attribute, impute, credit" (something to someone), from Old French ascrivre "to inscribe; attribute, impute," from Latin ascribere "to write in, enter in a list; add to in a writing," figuratively "impute, attribute," from ad "to" (see ad-) + scribere "to write" (from PIE root *skribh- "to cut"). The English spelling was conformed to Latin 16c. Related: Ascribed; ascribing.

"square stone for building or paving," mid-14c., from Old French aisseler, Medieval Latin arsella "a little board or shingle," diminutive of Latin assis "a board, plank," also spelled axis, which is perhaps not the same axis that means "axle." De Vaan regards the Latin spelling axis as a hyper-correction. The stone sense is peculiar to English. The meaning "thin slab of stone used as facing on a wall" is from 1823.