• IPA: /ˈsɛntɪnəl/

sentinel (plural sentinels)

1. A sentry or guard.
   • 1719- Daniel Defoe, Robinson Crusoe

     They promised faithfully to bear their confinement with patience, and were very thankful that they had such good usage as to have provisions and light left them; for Friday gave them candles (such as we made ourselves) for their comfort; and they did not know but that he stood sentinel over them at the entrance.

   • 18, Thomas Babington Macaulay, chapter 12, in The History of England from the Accession of James the Second, volume (please specify ), London: Longman, Brown, Green, and Longmans, OCLC 1069526323 ↗:

2. (computer science) a unique string of characters recognised by a computer program for processing in a special way; a keyword.

   The <xmp> tag is a sentinel that suspends web-page processing and displays the subsequent text literally.

3. Watch; guard.
   • 1625, Francis Bacon, Of Empire

     that princes do keep due sentinel

4. A sentinel crab.

• French: factionnaire, sentinelle
• German: Wache, Wachposten, Wächter, Wächterin
• Italian: sentinella
• Portuguese: sentinela, vigia
• Russian: часово́й
• Spanish: guarda, centinela

• German: Markierung, Schlüsselwort

sentinel (sentinels, present participle sentineling; past and past participle sentineled)

1. (transitive) To watch over as a guard.

   He sentineled the north wall.

2. (transitive) To post as guard.

   He sentineled him on the north wall.

3. (transitive) To post a guard for.

   He sentineled the north wall with just one man.

   • 1873, Harper's New Monthly Magazine (volume 46, page 562)

     The old-fashioned stoop, with its suggestive benches on either side, lay solitary and silent in the moonlight; the garden path, weedily overgrown since father's death, and sentineled here and there with ragged hollyhock, lay quiet and dew-laden […]

• French: regarder
• German: bewachen
• Portuguese: vigiar

1. A ghost town in California.
2. A town in Oklahoma.