RichThesaurus
on the qui vive
vs
sharp-sightedness
on the qui vive
adv
In a state of heightened vigilance, especially prior to battle.
sharp-sightedness
noun
The state of being sharp-sighted
How often have the words
on the qui vive
and
sharp-sightedness
occurred in a corpus of books?
(source:
Google Ngram Viewer
)