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[ad-ee-uh-bat-ik, ey-dahy-uh-]
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  1. occurring without gain or loss of heat (opposed to diabatic): an adiabatic process.

Origin of adiabatic

1875–80; < Greek adiábat(os) incapable of being crossed (a- a-6 + dia- dia- + ba- (stem of baínein to cross) + -tos verbal adjective suffix) + -ic; cf. diabatic
Related formsad·i·a·bat·i·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for adiabatic

Historical Examples

  • This is the line of no transmission of heat, therefore known as Adiabatic.

    Aviation Engines

    Victor Wilfred Pag

  • But let us assume that we have a compressor which shows an adiabatic pressure line.

  • The adiabatic lines, representing a fall of temperature of 1° Fahrenheit per 183 feet of ascent, serve for comparison.

    Sounding the Ocean of Air

    A. Lawrence Rotch

  • The straight dotted lines show the adiabatic decrease of temperature for ascending dry air.

    Sounding the Ocean of Air

    A. Lawrence Rotch

  • The temperature falls at the adiabatic rate in unsaturated air till the base of the cumulus cloud is reached.

    Sounding the Ocean of Air

    A. Lawrence Rotch

British Dictionary definitions for adiabatic


  1. (of a thermodynamic process) taking place without loss or gain of heat
  1. a curve or surface on a graph representing the changes in two or more characteristics (such as pressure and volume) of a system undergoing an adiabatic process

Word Origin

C19: from Greek adiabatos not to be crossed, impassable (to heat), from a- 1 + diabatos passable, from dia- across + bainein to go
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 adiabatic


1838, from Greek adiabatos "not to be passed through," from a- "not" + dia "through" (see dia-) + batos "passable," from bainein "to go" (see come).

Online Etymology Dictionary, © 2010 Douglas Harper

adiabatic in Science


  1. Occurring without gain or loss of heat. When a gas is compressed under adiabatic conditions, its pressure increases and its temperature rises without the gain or loss of any heat. Conversely, when a gas expands under adiabatic conditions, its pressure and temperature both decrease without the gain or loss of heat. The adiabatic cooling of air as it rises in the atmosphere is the main cause of cloud formation.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.