"close, termination," 1752, from expire + -y (4). Meaning "dying, death" is from 1790.
Entries linking to expiry
expire v.
c. 1400, "to die," from Old French expirer "expire, elapse" (12c.), from Latin expirare/exspirare "breathe out, blow out, exhale; breathe one's last, die," hence, figuratively, "expire, come to an end, cease," from ex "out" (see ex-) + spirare "to breathe" (see spirit (n.)). "Die" is the older sense in English; that of "breathe out" is attested from 1580s. Of laws, patents, treaties, etc., mid-15c. In 17c. also transitive. Related: Expired; expiring.
-y 4
suffix indicating state, condition, or quality; also activity or the result of it (as in victory, history, etc.), via Anglo-French and Old French -é, from Latin -ia, Greek -ia, from PIE *-a-, suffix forming abstract or collective nouns. It is etymologically identical with -ia and the second element in -cy, -ery, -logy, etc.