[ thur-muhl ]
See synonyms for: thermalthermals on

  1. Also thermic. of, relating to, or caused by heat or temperature: Buildings and sealed surfaces have a higher thermal capacity than soil and give up their heat more slowly at night.We speed up composting using a thermal treatment.

  2. of or relating to hot springs or hot baths: The bubbly, hot spring pool derives its name from the character of its thermal waters.

  1. designed to aid in or promote the retention of body heat: We keep a thermal blanket in the car during winter, just in case.

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

  1. thermals. thermal underwear.

Origin of thermal

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

Other words from thermal

  • ther·mal·ly, adverb
  • hy·per·ther·mal, adjective
  • hy·per·ther·mal·ly, adverb
  • non·ther·mal, adjective
  • non·ther·mal·ly, adverb

Words Nearby thermal Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use thermal in a sentence

British Dictionary definitions for thermal


/ (ˈθɜːməl) /

  1. Also: thermic (ˈθɜːmɪk) of, relating to, caused by, or generating heat or increased temperature

  2. hot or warm: thermal baths; thermal spring

  1. (of garments or fabrics) specially designed so as to have exceptional heat-retaining properties

  1. meteorol a column of rising air caused by local unequal heating of the land surface, and used by gliders and birds to gain height

  2. (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

Scientific definitions for thermal


[ thûrməl ]

  1. Relating to heat.

  1. 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.