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

After blowing off its gaseous outer layers, its core contracts. —Big Think, 3 Nov. 2025

Each color in the model corresponds to different temperatures and altitudes within WASP-18 b’s gaseous atmosphere. —Eric Lagatta, USA Today, 30 Oct. 2025

The brightening occurred as an increase in heat radiation from the sun vaporized icy materials embedded in its structure, creating a gaseous shell around its nucleus. —Anthony Wood, Space.com, 26 Oct. 2025

What’s in the Exhaust The strongest contributors to ozone loss from rockets are gaseous chlorine and soot. —New Atlas, 25 Oct. 2025

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