undertow
subsurface flow of water returning seaward from shore as result of wave action; average under-current which is moving offshore when waves are approaching a shore
en-GB/ˈʌndətəʊ/
en-US/ˈʌndɚˌtoʊ/
subsurface flow of water returning seaward from shore as result of wave action; average under-current which is moving offshore when waves are approaching a shore