[F., lit. ‘(long) live who?’ a sentinel’s challenge, intended to discover to which party the person challenged belongs, and properly requiring an answer of the form (vive) le roi, la France, etc.] On the qui vive, on the alert or look-out.
1726. Swift, in Pope’s Wks. (1871), VII. 82. It is imagined that I must be … alway upon the qui vive and the slip-slop.
1752. Fielding, Amelia, Wks. 1775, X. 223. Though he be a little too much on the qui-vive, he is a man of great honour.
1833. Marryat, P. Simple, lii. This put us all on the qui vive.
1883. E. P. Roe, in Harper’s Mag., Dec., 56/1. ‘What now?’ cried Burtis, all on the qui vive.
