What is the origin of 'sleep tight'?
Read moreOne of the mysteries of the English language finally explained.
noun
in phrase on the qui viveOn the alert or lookout.
‘duty requires the earnest liberal to spend most of his time on the qui vive for fascism’alert, awake, watchful, wide awake, observant, perceptive, percipient, acute, aware, noticing, heeding, heedful, mindful, vigilant, on guard, on one's guard, on one's toes, on the qui vive, on the lookoutView synonyms
Origin
Late 16th century: from French, literally ‘(long) live who?’, i.e. ‘on whose side are you?’, used as a sentry's challenge.
