I. | ̷ ̷ ̷ ̷| ̷ ̷ ̷ ̷ adjective
Etymology: under (II) + water, n.
1. : lying, growing, performed, worn, or operating below the surface of the water
underwater caverns
underwater operation of a submarine
underwater signaling
2. : being below the waterline of a ship
underwater body
underwater valve
3. of a security : not backed by assets : having no equity if all liabilities were paid
II. adverb
Etymology: under (II) + water, n.
: under the water : under the surface of the water
once stayed underwater for twenty-four hours — New Yorker
could move more quickly underwater — Sir Winston Churchill
III. ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ ̷ ̷ noun
Etymology: under (III) + water
: the water under the surface (as of the ocean)
fired from underwater
the underwaters were infested by submarines — Irish Statesman
knows the underwater of the bay … like the back of her hand — George Bradshaw