Also therm-, -therm.

Origin of thermo-

< Greek, combining form of thermós hot, thérmē heat Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for thermo-


before a vowel therm-

combining form
  1. related to, caused by, or measuring heatthermodynamics; thermophile

Word Origin for thermo-

from Greek thermos hot, thermē heat
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 thermo-

word-forming element meaning "hot, heat," used in scientific and technical words, from comb. form of Greek thermos "hot," therme "heat" (see thermal).

Online Etymology Dictionary, © 2010 Douglas Harper

thermo- in Medicine


  1. Heat:thermogenesis.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

thermo- in Science


  1. A prefix that means “heat,” as in thermometer.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.