n. [ L. sentina bilge water, hold of a ship, dregs: cf. F. sentine. ] A place for dregs and dirt; a sink; a sewer. [ Obs. ] Latimer. [ 1913 Webster ]

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 ]

v. t. [ imp. & p. p. Sentineled r Sentinelled; p. pr. & vb. n. Sentineling or Sentinelling. ] 1. To watch over like a sentinel. “To sentinel enchanted land.” [ R. ] Sir W. Scott. [ 1913 Webster ]

2. To furnish with a sentinel; to place under the guard of a sentinel or sentinels. [ 1913 Webster ]