gaseous

adjective

gas·​eous ˈga-sē-əs  ˈga-shəs 

1

: having the form of or being gas

also : of or relating to gases

2

a

: lacking substance or solidity

b

: gassy sense 3

… trick phrases and gaseous circumlocutions …

—Edwin Newman

gaseousness noun

Synonyms of gaseous

• rhetorical
• inflated
• gassy

Examples of gaseous in a Sentence

a substance changing from a liquid to a gaseous state

a pompous professor known for his gaseous lectures that often put students to sleep

Recent Examples on the Web

Scientists have observed this instability pattern in lake and ocean waves, cloud formation and the atmospheres of large gaseous planets such as Jupiter and Saturn. — Ashley Strickland, CNN Money, 5 Aug. 2026

One leading theory suggests that a large fraction of their total mass consists of gaseous envelopes composed of hydrogen and helium. — Chris Young july 30, Refractor, 30 July 2026

The problem with all those experiments was that the small, densely gaseous chambers used in the lab are nothing like your home. — Leanne Potts, Better Homes & Gardens, 30 July 2026

After validating the liquid Hydrogen Fuel System, the company completed testing of the Fuel Cell Hydrogen System, which supplies gaseous hydrogen to the fuel cell. — Maria Mocerino, Interesting Engineering, 26 July 2026

Word History

First Known Use

1799, in the meaning defined at sense 1

Rhymes for gaseous

• caseous

Kids Definition

gaseous

adjective

gas·​eous ˈgas-ē-əs 

ˈgash-əs

1

: having the form of or being gas

2

: of or relating to gas

3

: lacking solidity

Medical Definition

gaseous

adjective

gas·​eous ˈgas-ē-əs  ˈgash-əs 

: having the form of or being gas

also : of or relating to gases