"science of the motion of air or other gases," 1837, from aero- "air" + dynamics.
word-forming element meaning "air, atmosphere; gases," in 20c. use with reference to aircraft or aviation, from Greek aēr (genitive aeros) "air, lower atmosphere" (see air (n.1)).
as a branch of physics that calculates motions in accordance with the laws of force, by 1752, from dynamic (adj.); also see -ics. As "the moving physical or moral force in anything," by 1833.