1680s, from un- (1) "not" + present participle of aspire (v.).
Entries linking to unaspiring
un- 1
prefix of negation, Old English un-, from Proto-Germanic *un- (source also of Old Saxon, Old Frisian, Old High German, German un-, Gothic un-, Dutch on-), from PIE *n- (source of Sanskrit a-, an- "not," Greek a-, an-, Old Irish an-, Latin in-), combining form of PIE root *ne- "not." Often euphemistic (such as untruth for "lie").
The most prolific of English prefixes, freely and widely used in Old English, where it forms more than 1,000 compounds. It underwent a mass extinction in early Middle English, but emerged with renewed vigor 16c. to form compounds with native and imported words. It disputes with Latin-derived cognate in- (1) the right to form the negation of certain words (indigestable/undigestable, etc.), and though both might be deployed in cooperation to indicate shades of meaning (unfamous/infamous), typically they are not.
It also makes words from phrases (such as uncalled-for, c. 1600; undreamed-of, 1630s; uncome-at-able, 1690s; unputdownable, 1947, of a book; un-in-one-breath-utterable, Ben Jonson; etc., but the habit is not restricted to un-; such as put-up-able-with, 1812). As a prefix in telegramese to replace not and save the cost of a word, it is attested by 1936.
aspire v.
"strive for, seek eagerly to attain, long to reach," c. 1400, aspiren, from Old French aspirer "aspire to; inspire; breathe, breathe on" (12c.), from Latin aspirare "to breathe upon, blow upon, to breathe," also, in transferred 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" (see ad-) + spirare "to breathe" (see spirit (n.)).
The notion is of "panting with desire," or perhaps of rising smoke. The literal sense of "breathe, exhale" (1530s) is rare in English. Related: Aspired; aspiring.