underwater
adjective
°beneath the surface of the water, or of or pertaining to the region beneath the water surface.
°(nautical) beneath the water line of a vessel.
noun
°underlying water or body of water, for example in an aquifer or the deep ocean.
°A type of lure which lies beneath the water surface.
verb
°to water or irrigate insufficiently.
synonyms: subaqueous, upside down