[ gas-ee-uh s, gash-uh s ]
/ ˈgæs i əs, ˈgæʃ əs /


existing in the state of a gas; not solid or liquid.
pertaining to or having the characteristics of gas.
Informal. lacking firmness or solidity; uncertain; not definite.

Nearby words

  1. gasconade,
  2. gascony,
  3. gascoyne-cecil,
  4. gaseity,
  5. gaselier,
  6. gaseous diffusion,
  7. gash,
  8. gasholder,
  9. gashouse,
  10. gasiform

Origin of gaseous

First recorded in 1790–1800; gas + -eous

Related forms Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for gaseous

British Dictionary definitions for gaseous


/ (ˈɡæsɪəs, -ʃəs, -ʃɪəs, ˈɡeɪ-) /


of, concerned with, or having the characteristics of a gas
Derived Formsgaseousness, noun

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 gaseous



1799, from gas (n.) + -ous.

Online Etymology Dictionary, © 2010 Douglas Harper

Medicine definitions for gaseous


[ găsē-əs, găshəs ]


Of, relating to, or existing as a gas.
Full of or containing gas; gassy.

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

Science definitions for gaseous


[ găs ]

One of four main states of matter, composed of molecules in constant random motion. Unlike a solid, a gas has no fixed shape and will take on the shape of the space available. Unlike a liquid, the intermolecular forces are very small; it has no fixed volume and will expand to fill the space available.
Related formsgaseous adjective (găsē-əs, găshəs)

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.