Sen"ti*nel, n. [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.]
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. Zool.
A marine crab (Podophthalmus vigil) native of the Indian Ocean, remarkable for the great length of its eyestalks; -- called also sentinel crab.
© Webster 1913.
Sen"ti*nel, v. t. [imp. & p. p. Sentineled (?) or Sentinelled; p. pr. & vb. n. Sentineling or Sentinelling.]
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.