[thur-muh s]


a vacuum bottle or similar container lined with an insulating material, such as polystyrene, to keep liquids hot or cold.


Origin of thermos

First recorded in 1905–10; formerly a trademark
Also called thermos bottle. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for thermos

Contemporary Examples of thermos

Historical Examples of thermos

  • In their places, suddenly, there were the thermos and the binoculars.

    The Hohokam Dig

    Theodore Pratt

  • The day of that blessed comfort of the trail, the thermos flask, was not yet.

  • So she gets out the sandwiches and the thermos bottle and we take it that way.

    Torchy and Vee

    Sewell Ford

  • They filled the thermos bottle that had so puzzled Tom, and then sallied forth.

  • They had a thermos bottle of cold tea which they referred to as “rum.”

    The Cricket

    Marjorie Cooke

British Dictionary definitions for thermos


Thermos flask


trademark a type of stoppered vacuum flask used to preserve the temperature of its contentsSee also Dewar flask
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for thermos



trademark registered in Britain 1907, invented by Sir James Dewar (patented 1904 but not named then), from Greek thermos "hot" (see thermal). Dewar built the first one in 1892, but it was first manufactured commercially in Germany in 1904, when two glass blowers formed Thermos GmbH. Supposedly the company sponsored a contest to name the thing, and a Munich resident won with a submission of Thermos.

Online Etymology Dictionary, © 2010 Douglas Harper