ther·​mos | \ ˈthər-məs How to pronounce thermos (audio) \

Definition of thermos

: a container (such as a bottle or jar) with a vacuum between an inner and outer wall used to keep material and especially liquids either hot or cold for considerable periods

Examples of thermos in a Sentence

Recent Examples on the Web

Each recipe makes either a single flask-size portion (six ounces) or a thermos-size batch (17 ounces). Ac Shilton, Outside Online, "Flask Cocktails You Can Drink in the Backcountry," 13 Sep. 2019 What comes out of the thermos is a pile of dark grey sludge. Jennifer Leman, Popular Mechanics, "Watch This Hong Kong Protester Instantly Neutralize Tear Gas," 3 Sep. 2019 An older sister poured hot water from a thermos into paper cups to warm us. Los Angeles Times, "One is Chinese. One is American. How a journalist discovered and reunited identical twins," 8 Aug. 2019 Dress warmly, bring a thermos with a warm beverage and bring your bug spray. Joan Rusek,, "Need an attitude adjustment – catch ‘A New Brain’ at River Street Playhouse: Valley Views," 5 Aug. 2019 Lili, the older woman with the thermos who called me a weirdo, sat next to me again during a small group exercise. Emma Grey Ellis, WIRED, "I Think I Hated This Tech Conference on Psychedelics," 8 June 2019 Many people start the morning by dropping a handful of tea leaves into a thermos to carry with them and refill with more hot water throughout the day. National Geographic, "In search of the perfect cup of tea," 14 Mar. 2019 In March, K-9 dog Bettie helped agents discover a thermos stuffed with 2 pounds of pork belonging to a passenger on a flight from China. Eliza Fawcett,, "‘We see meats of all kinds’: U.S. customs agents say seizure of African rodent meat at O’Hare not outlandish," 3 July 2019 Grab a tumbler of cold brew the size of your head. Sling a thermos of your best Italian brew over your shoulder. Michelle Santiago Cortés,, "Krispy Kreme Wants To Give You A Free Doughnut Tomorrow – No Strings Attached," 7 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'thermos.' 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 thermos

1907, in the meaning defined above

History and Etymology for thermos

from Thermos, a trademark

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Statistics for thermos

Last Updated

30 Sep 2019

Look-up Popularity

Time Traveler for thermos

The first known use of thermos was in 1907

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More Definitions for thermos



English Language Learners Definition of thermos

: a container that keeps liquids hot or cold for long periods of time


ther·​mos | \ ˈthər-məs How to pronounce thermos (audio) \

Kids Definition of thermos

: a container (as a bottle or jar) that has a vacuum between an inner and an outer wall and is used to keep liquids hot or cold for several hours

More from Merriam-Webster on thermos

Rhyming Dictionary: Words that rhyme with thermos

Spanish Central: Translation of thermos

Nglish: Translation of thermos for Spanish Speakers

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