tran·​quil·​ize | \ˈtraŋ-kwə-ˌlīz, ˈtran-\
variants: or less commonly tranquillize
tranquilized also tranquillized; tranquilizing also tranquillizing

Definition of tranquilize 

transitive verb

: to make tranquil or calm : pacify especially : to relieve of mental tension and anxiety by means of drugs

intransitive verb

1 : to become tranquil : relax sense 1

2 : to make one tranquil

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Synonyms & Antonyms for tranquilize


becalm, calm, compose, lull, lullaby, quiet, quieten [chiefly British], salve, settle, soothe, still


agitate, discompose, disquiet, disturb, key (up), perturb, upset, vex

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Examples of tranquilize in a Sentence

They tranquilized the bear with a dart so that it could be safely moved to a different area. at long last the crying baby was tranquilized by the steady rocking of her cradle

Recent Examples on the Web

They were tranquilized and captured just before 1 p.m., according to the MTA. Sarah Maslin Nir, The Seattle Times, "Not Your Average Subway Delay: Hungry Goats on the Tracks," 20 Aug. 2018 The jaguar was tranquilized by a vet team and returned to its enclosure. Fox News, "Author Shelby Steele on race relations, equality in America," 16 July 2018 While elsewhere in the world naturalists were studying bears by tranquilizing them and putting trackers on them, or doing chemical analysis of their blood and bodily wastes, Mr. Russell wanted no part of that. New York Times, "Charlie Russell, Who Befriended Bears, Dies at 76," 10 May 2018 The purpose of that medication is not really to treat an illness, but to tranquilize them. Molly Hennessy-fiske,, "Lawsuit alleges improper medication of migrant children in federal shelters," 21 June 2018 The animal, later identified as a rhesus macaque named Dawkins, was tranquilized two hours after initially escaping and transported to a sanctuary, KSAT reported. Jennifer Earl, Fox News, "Monkey escapes crate at San Antonio airport, flees to baggage area," 22 May 2018 The lions have been tranquilized to enable the police and the anti-poaching unit to continue the investigation, according to Fox’s statement. Deanna Paul, Washington Post, "Suspected poachers were looking for rhinos. They found hungry lions instead, game reserve owner says.," 5 July 2018 After tranquilizing the bear, officials were able to recover Bhatara’s body. Fox News, "Injured bear fatally mauls man who attempted to take a selfie with it," 7 May 2018 Six lions were tranquilized so police could search the area the next day, alongside the reserve’s anti-poaching unit and other specialists. Jewel Wicker, Teen Vogue, "Lions Kill Suspected Rhino Poachers in South Africa," 6 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'tranquilize.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of tranquilize

1623, in the meaning defined at transitive sense

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Statistics for tranquilize

Last Updated

5 Dec 2018

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Time Traveler for tranquilize

The first known use of tranquilize was in 1623

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English Language Learners Definition of tranquilize

: to use a drug to cause (a person or animal) to become very relaxed and calm


transitive verb
variants: or chiefly British tranquillize or tranquillise \ˈtraŋ-​kwə-​ˌlīz, ˈtran-​ \
tranquilized or chiefly British -lized or tranquilised; tranquilizing or chiefly British tranquilizing or tranquilising

Medical Definition of tranquilize 

: to make tranquil or calm especially : to relieve of mental tension and anxiety by means of drugs

Other Words from tranquilize

tranquilization or chiefly British tranquillization or tranquillisation \ˌtraŋ-​kwə-​lə-​ˈzā-​shən, ˌtran-​ \ noun

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having a pattern of small flowers

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