sentinel

[ sen-tn-l ]

noun

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

   The cats were the sentinels of the house, patrolling constantly for rodents, dogs, and other invaders.

   Synonyms: lookout, watch, guard, sentry

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

   Lincoln refused to make his home mansion a garrison during the Civil War, but plain-clothes sentinels did patrol the property

   Synonyms: lookout, watch, guard, sentry

3. Digital Technology. tag ¹( def 9a ).
4. Medicine/Medical. an indication or mark that a disease is present or prevalent:

   New viruses in the wastewater can be used as sentinels of future outbreaks.

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:

   This monument sentinels each soldier's grave as a shrine.

adjective

1. Medicine/Medical. relating to or being an indication of a disease's presence or prevalence:

   Pregnant women attending prenatal appointments serve as a sentinel population for the prevalence of malaria in the region.

   The sentinel lymph nodes are the first lymph nodes that the cancer cells reach if they spread.

sentinel

/ ˈsɛntɪnəl /

noun

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

1. to guard as a sentinel
2. to post as a sentinel
3. to provide with a sentinel

Other Words From

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

Word History and Origins

Origin of sentinel¹

First recorded in 1570–80; from Middle French sentinelle, from Italian sentinella, derivative of Old Italian sentina “vigilance,” from Latin sent(īre) “to feel” + -īna -ine ²

Word History and Origins

Origin of sentinel¹

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

Example Sentences

Beal noted one of the sentinel signs that a farm has been infected is dead barn cats that have drunk the infected, raw milk.

From Los Angeles Times

One of the more ambitious scenes was a sentinel attack that decimates the mutants.

From Los Angeles Times

Intriguingly, the system being attacked normally works as a sentinel or guard, whose job it is to detect invading viruses.

From Science Daily

The area has been named a sentinel landscape, a federally led effort to promote sustainable land-use practices near military installations.

From Los Angeles Times

“This is a sentinel species,” Pozo said, referring to the canary-in-a-coal mine effect where one species can say a lot about an ecosystem.

From Seattle Times