one of the wavy lines or ridges produced, especially on sand, by the action of waves, wind, or the like.
2.
one of such forms preserved in sandstone or siltstone.
Origin
1825-35
Examples from the web for ripple mark
Rhomboid ripple mark, indicator of current direction and environment.
British Dictionary definitions for ripple mark
ripple mark
noun
1.
one of a series of small wavy ridges of sand formed by waves on a beach, by a current in a sandy riverbed, or by wind on land: sometimes found fossilized on bedding planes of sedimentary rock