perdu
Stationed in an exposed or hazardous position; hidden in ambush. Originally as sentinel perdu.
obsolete
In a dangerous situation; lost, desperate.
archaic
Among certain grizzled sea-gossips of the gun decks and forecastle went a rumor perdue […]
Hidden; concealed from sight. Chiefly with lie.
archaic
He should lie Perdue who is to walk the round.
Where it comes from
Borrowed from Middle French perdu, originally after sentinelle perdue.
Adapted from the Wiktionary entry perdu (CC BY-SA 4.0).