rough waves; raging waves; stormy seas
Describes sea conditions with high, violent, or dangerous waves. Often used in weather reports, literary descriptions, or warnings.
Rough waves crashed against the shore due to the typhoon.
Rough waves are expected today, so please stay away from the sea.
Compound of 荒い (rough, violent) and 波 (wave). The phrase is transparent and follows standard Japanese adjective-noun modification.