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.

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)

sentineled, sentineling , sentinelled, sentinelling .

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 Word Forms

• sentinellike adjective
• sentinelship noun
• unsentineled adjective
• unsentinelled 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

Dogs get more tick bites and are tested more often for vector-borne diseases than people, so they can be sentinels for their owners.

Read more on Los Angeles Times

All of Orange County Fire Watch’s sentinels started as volunteers with the county parks or the Irvine Ranch Conservancy, which boast pools of 1,200 and 500 volunteers, respectively.

Read more on Los Angeles Times

"You've just murdered a sentinel of time and elemental spirit of Northumberland," he raged on social media.

Read more on BBC

The first season’s guards present the games as opportunities, assuring the players that the machine gun-toting sentinels in pink jumpsuits aren’t there to hurt them.

Read more on Salon

While the latter two were essentially vaporized by the fire, the burned shells of the others remain, steel sentinels left ravaged by the flames.

Read more on Los Angeles Times