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

The police feel that they’re getting an always available sentinel standing guard in front of the homes of repeat victims of crime.

From MIT Technology Review

These sentinels stay in contact with systems equipped to issue streams of calibrated instructions to the parts of the body that can act to maintain stability.

From Popular-Science

This clinical strategy relies both on infected individuals coming to sentinel hospitals and medical authorities who are influential and persistent enough to raise the alarm.

From No Straight News

That’s the Kinyarwandan name for the eight volcanoes — two active, six dormant — that stand sentinel over the tripartite border of Uganda, Rwanda and Congo.

From Washington Post

It matters where tohorā feed and how their populations recover from whaling because the species is recognised as a sentinel for climate change throughout the Southern Hemisphere.

From Popular-Science

The program, Satellite Sentinel Project, is designed to document and deter atrocities against civilians.

From The Daily Beast

Clooney heads the Satellite Sentinel Project, which monitors human rights abuses.

From The Daily Beast

They were reading the Lodi News-Sentinel and the Indianapolis Star and the Milwaukee Journal.

From The Daily Beast

“The more I thought about it, the more sense it made,” she told the Sun-Sentinel in 1998.

From The Daily Beast

A web promotion for X-Men: Days of Future Past indicated that the character had been killed by a Sentinel in 2011.

From The Daily Beast

The Café tender was asleep in his chair; the porter had gone off; the sentinel alone kept awake on his post.

From Project Gutenberg

The sentinel was singing a sequedilla above; and its notes came to them with the wailing blast.

From Project Gutenberg

The sentinel stood leaning against a tree, his head on his breast, apparently sound asleep.

From Project Gutenberg

A few miles in advance of the island stands the beautiful Falcon Rock, like a sentinel upon the look-out.

From Project Gutenberg

At length he approached a sentinel, who called “halt” three times without response, and then shot the lieutenant dead.

From Project Gutenberg