1845, from French acrobate "tightrope-walker" (14c.) and directly from a Latinized form of Greek akrobates "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 -bates "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."
Middle English -ik, -ick, word-forming element making adjectives, "having to do with, having the nature of, being, made of, caused by, similar to," from French -ique and directly from Latin -icus or from cognate Greek -ikos "in the manner of; pertaining to." From PIE adjective suffix *-(i)ko, which also yielded Slavic -isku, adjectival suffix indicating origin, the source of the -sky (Russian -skii) in many surnames. In chemistry, indicating a higher valence than names in -ous (first in benzoic, 1791).
In Middle English and after often spelled -ick, -ike, -ique. Variant forms in -ick (critick, ethick) were common in early Modern English and survived in English dictionaries into early 19c. This spelling was supported by Johnson but opposed by Webster, who prevailed.