Origin and history of *gwa-

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").

"without transference, impossible (to heat)," 1838, with -ic + Greek adiabatos "not to be passed" (of rivers, etc.), from a- "not" (see a- (3)) + diabatos "to be crossed or passed, fordable," from dia "through" (see dia-) + batos "passable," from bainein "to go, walk, step" (from PIE root *gwa- "to go, come"). In thermodynamics, of a change in volume without change in heat.