gravity wave

WordReference Random House Unabridged Dictionary of American English © 2026

grav′ity wave′, 

1. Astronomy See gravitational wave. 
2. Hydraulics a wave created by the action of gravity on local variations in the density of a stratified fluid, as the atmosphere, or at an interface between fluids of different density, as a liquid and a gas.
• 1875–80

Collins Concise English Dictionary © HarperCollins Publishers::

gravity wave noun

1. a surface wave on water or other liquid propagated because of the weight of liquid in the crests
   See also: gravitational wave