Entry 1 sense Webster, 1913 Longevity /lôn-jĕv'-ət-ē/ · Lon·gev·i·ty · IPA /lɑnˈd͡ʒɛv.ə.ti/ 01 n. Long duration of life; length of life. 1. Long duration of life; length of life. “The instances of longevity are chiefly amongst the abstemious.” — Arbuthnot.