[ thur-muh l ]
/ ˈθɜr məl /


Also thermic. of, relating to, or caused by heat or temperature: thermal capacity.
of, relating to, or of the nature of thermae: thermal waters.
designed to aid in or promote the retention of body heat: a thermal blanket.


Meteorology. a rising air current caused by heating from the underlying surface, especially such a current when not producing a cloud.
thermals. thermal underwear.

Origin of thermal

First recorded in 1750–60; therm- + -al1

OTHER WORDS FROM thermal Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2020

Example sentences from the Web for thermal

British Dictionary definitions for thermal

/ (ˈθɜːməl) /


Also: thermic (ˈθɜːmɪk) of, relating to, caused by, or generating heat or increased temperature
hot or warmthermal baths; thermal spring
(of garments or fabrics) specially designed so as to have exceptional heat-retaining properties


meteorol a column of rising air caused by local unequal heating of the land surface, and used by gliders and birds to gain height
(plural) thermal garments, esp underclothes

Derived forms of thermal

thermally, adverb
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

Medical definitions for thermal

[ thûrməl ]


Of, relating to, using, producing, or caused by heat.
Intended or designed in such a way as to help retain body heat.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for thermal

[ thûrməl ]


Relating to heat.


A usually columnar mass of warm air that rises in the lower atmosphere because it is less dense than the air around it. Thermals form because the ground surface is heated unevenly by the Sun. The air usually rises until it is in equilibrium with the air surrounding it.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.