[ sen-tn-l ]
See synonyms for: sentinelsentineledsentinelingsentinelled on

  1. a person or thing that watches or stands as if watching.

  2. a soldier stationed as a guard to challenge all comers and prevent a surprise attack: to stand sentinel.

  1. Digital Technology. tag1 (def. 9a).

verb (used with object),sen·ti·neled, sen·ti·nel·ing or (especially British) sen·ti·nelled, sen·ti·nel·ling.
  1. to watch over or guard as a sentinel.

Origin of sentinel

1570–80; <Middle French sentinelle<Italian sentinella, derivative of Old Italian sentina vigilance (Latin sent(īre) to observe) + -īna-ine2)

Other words for sentinel

Other words from sentinel

  • sen·ti·nel·like, adjective
  • sen·ti·nel·ship, noun
  • un·sen·ti·neled, adjective
  • un·sen·ti·nelled, adjective

Words Nearby sentinel Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use sentinel in a sentence

British Dictionary definitions for sentinel


/ (ˈsɛntɪnəl) /

  1. a person, such as a sentry, assigned to keep guard

  2. computing a character used to indicate the beginning or end of a particular block of information

verb-nels, -nelling or -nelled (tr)
  1. to guard as a sentinel

  2. to post as a sentinel

  1. to provide with a sentinel

Origin of sentinel

C16: from Old French sentinelle, from Old Italian sentinella, from sentina watchfulness, from sentire to notice, from Latin

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012