mid-15c., from O.Fr. aspirer
"aspire to, inspire" (12c.), from L. aspirare
"to breathe upon, to breathe," also, in transf. senses, "to be favorable to, assist; to climb up to, to endeavor to obtain, to reach to, to seek to reach; infuse," from ad-
"to" + spirare
"to breathe" (see spirit
). The notion is of "panting with desire," or perhaps of rising smoke.