qui vive

American  

[kee veev] / ki ˈviv /

1. who goes there? (used as a sentry's challenge)

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idioms

1. on the qui vive, on the alert; watchful.

   Special guards were on the qui vive for trespassers.

qui vive British  

/ ˌkiː ˈviːv /

noun

1. on the alert; attentive

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Etymology

Origin of qui vive

1720–30; < French: literally, (long) live who? (i.e., on whose side are you?)

Example Sentences

"Qui vive?" cried out one of the sentries on the rock.

From Newton Forster by Marryat, Frederick

Aurilly felt this, and pointed out the sentinel, who, now observing, called out, "Qui vive!"

From The Forty-Five Guardsmen by Dumas père, Alexandre

It was but a few days after, when a cry of Qui vive, twice repeated, was heard from the river.

From France and England in North America; a Series of Historical Narratives — Part 3 by Parkman, Francis

"Qui vive?" shouted a voice from the underwood near them.

From The King's Warrant A Story of Old and New France by Engelbach, Alfred H.

The watchword is Qui vive? and the answer is L’état c’est moi—that was one of his favourite remarks, you know. 

From The Toys of Peace, and other papers by Saki