WordReference Random House Learner's Dictionary of American English © 2025
un•der•seas /ˌʌndɚˈsiz/USA pronunciation
adv.
WordReference Random House Unabridged Dictionary of American English © 2025- Nauticalbeneath the surface of the sea.
un•der•seas
(un′dər sēz′),USA pronunciation adv.
- Nauticalbeneath the surface of the sea.
- undersea + -s1 1675–85
'underseas' also found in these entries (note: many are not synonyms or translations):