C18: from French, literally: long live who?, sentry's challenge (equivalent to "Towhose party do you belong?" or "Whose side do you support?")
qui vive? in American English
(kiˈviv)
who goes there?
a sentry's challenge
Idioms:
on the qui vive
Word origin
Fr, (long) live who? (i.e., which monarch or ruler do you support?, whose side areyou on?), 3d pers. sing., pres. subj., of vivre, to live (< L vivere) + qui, who (< L)