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

Example Sentences

Recent Examples on the Web More than 3,000 lunchboxes and 1,000 thermoses sit on floor-to-ceiling shelves that line the walls. Teresa Nowakowski, Smithsonian Magazine, 14 Mar. 2023 On Christmas morning, instead of gathering around a tree and opening presents, the three of us would load our car with a cooler full of chapatis wrapped in tinfoil and thermoses packed with sabji and drive to one of America’s natural wonders to picnic. Meena Venkataramanan, Washington Post, 5 Mar. 2023 This rugged travel mug doubles as a thermos to keep drinks hot and cold and requires only the push of a button to open. Danny Perez, Popular Mechanics, 19 Jan. 2023 Someone will deliver it to your room in a thermos. Christopher Elliott, Forbes, 23 Oct. 2021 At Alaska’s Alyeska Resort, a tester-ski patroller ended up with soaked layers because of a thermos with a poor seal. Charlie Ebbers, Outside Online, 18 Oct. 2022 Screw on the top of the thermos, label it and place it right on the buffet table. People Staff, Peoplemag, 18 Nov. 2022 Put your loose-leaf tea in the basket, secure the lid, drop it in the thermos, and pour water over the top. Scott Gilbertson, WIRED, 8 Nov. 2022 Lastly, preheat the thermos with hot water before adding the soup to ensure that the contents have the best opportunity to stay hot. Briana Riddock, Outside Online, 7 Nov. 2022 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'thermos.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


from Thermos, a trademark

First Known Use

1907, in the meaning defined above

Time Traveler
The first known use of thermos was in 1907

Dictionary Entries Near thermos

Cite this Entry

“Thermos.” Dictionary, Merriam-Webster, Accessed 27 May. 2023.

Kids Definition


ther·​mos ˈthər-məs How to pronounce thermos (audio)
: a container (as a bottle) with a vacuum between an inner and an outer wall used to keep material (as liquids) hot or cold

More from Merriam-Webster on thermos

Last Updated: - Updated example sentences
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