sentinel

[ sen-tn-l ]
/ ˈsɛn tn l /

noun

a person or thing that watches or stands as if watching.
a soldier stationed as a guard to challenge all comers and prevent a surprise attack: to stand sentinel.
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.

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)

Related forms

sen·ti·nel·like, adjectivesen·ti·nel·ship, nounun·sen·ti·neled, adjectiveun·sen·ti·nelled, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for sentinel

British Dictionary definitions for sentinel

sentinel

/ (ˈsɛntɪnəl) /

noun

a person, such as a sentry, assigned to keep guard
computing a character used to indicate the beginning or end of a particular block of information

verb -nels, -nelling or -nelled (tr)

to guard as a sentinel
to post as a sentinel
to provide with a sentinel

Word Origin for 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