Sentinel \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. [1913 Webster]

The sentinels who paced the ramparts. --Macaulay. [1913 Webster]

2. Watch; guard. [Obs.]

"That princes do keep due sentinel." --Bacon. [1913 Webster]

3. (Zool.) A marine crab (Podophthalmus vigil) native of the Indian Ocean, remarkable for the great length of its eyestalks; -- called also sentinel crab. [1913 Webster]

Source: The Collaborative International Dictionary of English v.0.48
 

Sentinel \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. (Zo["o]l.) A marine crab (Podophthalmus vigil) native of the Indian Ocean, remarkable for the great length of its eyestalks; -- called also sentinel crab.

Source: Webster's Revised Unabridged Dictionary (1913)