sentry Meaning, Definition & Usage

  1. noun a person employed to keep watch for some anticipated event
    lookout; picket; watch; lookout man; scout; spotter; sentinel.

WordNet

Sen"try noun
Etymology
Probably from OF. senteret a little patch; cf. F. sentier path, and OF. sente. See Sentinel.
Wordforms
plural Sentires
Definitions
  1. (Mil.) A soldier placed on guard; a sentinel.
  2. Guard; watch, as by a sentinel.
    Here toils, and death, and death's half-brother, sleep, Forms terrible to view, their sentry keep. Dryden.

Webster 1913