early 14c., "inferior officer in the church," from Old French acolite or directly from Medieval Latin acolytus (Late Latin acoluthus), from Greek akolouthos "following, attending on," as a noun, "a follower, attendant," literally "having one way," from a- "together with," copulative prefix (see a- (3)), + keleuthos "a way, road, path, course, journey," which is of unknown etymology. The word was in late Old English as acolitus, a Latin form; in early modern English a corrected form acolythe was used.
"highest point," 1560s, from Greek akmē "(highest) point, edge; peak of anything," hence "prime (of life, etc.), the best time" (from PIE *ak-ma-, suffixed form of root *ak- "be sharp, rise (out) to a point, pierce"). In English it was written in Greek letters until c. 1620. The U.S. grocery store chain was founded 1891 in Philadelphia, Pennsylvania.
late 15c., "admit or show one's knowledge," a blend of Middle English aknow "admit or show one's knowledge" and Middle English knowlechen "admit, acknowledge" (c. 1200; see knowledge). Middle English aknow is from Old English oncnawan "understand, come to recognize," from on (see on (prep.)) + cnawan "recognize;" see know). "By 16th c. the earlier vbs. knowledge and a(c)know ... were obs., and acknowledge took their place" [OED]. In the merger, an unetymological -c- slipped in; perhaps the explanation is that when English kn- became a simple "n" sound, the -c- stepped up to preserve, in this word, the ancient "kn-" sound. Related: Acknowledged; acknowledging.
compound adjectival word-forming element of Latin origin, attached to verb stems and expressing intensity of action: "given to, inclined to, abounding in," or expressing intensity of physical or mental action, from Latin -aci- (nominative -ax, accusative -acem), noun ending used with verbal stems (see -acea), + -ous. The accompanying nouns are formed in -acity.