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

Ahead of our return to the city, we drive back up the ridge, back through Burguete, the inn still shuttered, and up to Roncesvalles, where the old monastery looms like a sentinel over the pass.

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Climate change is sure to batter this stone sentinel with higher seas and stronger storms.

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"Since dolphins are considered environmental sentinels for toxic exposures in marine environments," Dr. David Davis at the Miller School of Medicine explains, "there are concerns about human health issues associated with cyanobacterial blooms."

Read more on Science Daily

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

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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