c. 1200, o cros, "in the shape of a cross;" c. 1300, a-croiz, "in a crossed position;" early 14c., acros, "from one side to another;" a contraction of Anglo-French an cros, literally "on cross;" see a- (1) + cross (n.)). Meaning "on the other side (as a result of crossing)" is from 1750. In crossword puzzle clues from 1924. Spelling acrost, representing a dialectal or vulgar pronunciation, is attested by 1759. Phrase across the board "embracing all categories" (1945) is said to be originally from horse-racing, in reference to a bet of the same amount of money on a horse to win, place, or show. To get (something) across "make (something) understood or appreciated" is by 1913, probably from earlier theater expression get (something) across the footlights, perform it so as to be received by the audience (1894).
"elevated part of a Greek city," often the site of original settlement and usually a citadel, 1660s, from Latinized form of Greek akropolis "citadel" (especially, with capital A-, that of Athens), from akros "highest, upper" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + polis "city" (see polis). The plural would be acropoles.
"morbid fear of heights," 1887, medical Latin, from Greek akros "at the end, topmost" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + -phobia "fear." Coined by Italian physician Dr. Andrea Verga in a paper describing the condition, from which Verga himself suffered.In this paper, read somewhat over a year ago at the congress of alienists at Pavia, the author makes confession of his own extreme dread of high places. Though fearless of the contagion of cholera, he has palpitations on mounting a step-ladder, finds it unpleasant to ride on the top of a coach or to look out of even a first-story window, and has never used an elevator. [abstract of Verga's report in American Journal of Psychology, November 1888]
word formed from the first letters of a series of words, 1943, American English coinage from acro- + -onym "name" (abstracted from homonym; ultimately from PIE root *no-men- "name"). With the exception of cabalistic esoterica and acrostic poetry, this way of forming words was exceedingly uncommon before 20c. For distinction of use (regretfully ignored on this site), see initialism.
"gigantism due to activity of pituitary after normal growth has ceased," 1886, from French acromégalie, from medical Latin acromegalia, from Greek akron "extremity, highest point, mountain peak, headland," neuter of akros "at the furthest point" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + megas "great" (fem. megale; from PIE root *meg- "great"). Said in contemporary literature to have been coined 1885 by French physician Dr. Pierre Marie.
1845, from French acrobate "tightrope-walker" (14c.) and directly from a Latinized form of Greek akrobatēs "rope dancer, gymnastic performer," which is related to akrobatos "going on tip-toe, climbing up high," from akros "topmost, at the point end" (from PIE root *ak- "be sharp, rise (out) to a point, pierce") + Greek agential element -batēs "one that goes, one that treads (in some manner), one that is based," from -batos, verbal adjective from stem of bainein "to go, walk, step" (from PIE root *gwa- "to go, come").
1540s, "quality of being sharp or pungent in taste," from French acrimonie or directly from Latin acrimonia "sharpness, pungency of taste," figuratively "acrimony, severity, energy," abstract noun from acer "sharp" (fem. acris), from PIE root *ak- "be sharp, rise (out) to a point, pierce") + -monia suffix of action, state, condition (see -mony). Figurative extension to personal sharpness or bitterness is by 1610s.