Entry 4 senses · 2 variants Webster, 1913 Perdu /(pẽr*dū" [or] pẽr"dū̇)/ · Per·du · IPA /pəːˈdjuː/ n. a. 01 n. One placed on watch, or in ambush. 1. One placed on watch, or in ambush. 2. A soldier sent on a forlorn hope. 02 a. Lost to view; in concealment or ambush. 1. Lost to view; in concealment or ambush. “He should lie perdue who is to walk the round.” — Fuller. 2. Accustomed to, or employed in, desperate enterprises; hence, reckless; hopeless.