sentinel Meaning, Definition & Usage

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

WordNet

Sen"ti*nel noun
Etymology
F. sentinelle (cf. It. sentinella); probably originally, a litle path, the sentinel's beat,, and a dim. of a word meaning, path; cf. F. sente path. L. semita; and OF. sentine, sentele, senteret, diminutive words. Cf. Sentry.
Definitions
  1. One who watches or guards; specifically (Mil.), a soldier set to guard an army, camp, or other place, from surprise, to observe the approach of danger, and give notice of it; a sentry.
    The sentinels who paced the ramparts. Macaulay.
  2. Watch; guard. Obs. "That princes do keep due sentinel." Bacon.
  3. (Zoöl.) A marine crab (Podophthalmus vigil) native of the Indian Ocean, remarkable for the great length of its eyestalks; -- called also sentinel crab.
Sen"ti*nel transitive verb
Wordforms
imperfect & past participle Sentineled or Sentinelled; present participle & verbal noun Sentineling or Sentinelling
Definitions
  1. To watch over like a sentinel. "To sentinel enchanted land." R. Sir W. Scott.
  2. To furnish with a sentinel; to place under the guard of a sentinel or sentinels.

Webster 1913