I. | ̷ ̷ ̷ ̷| ̷ ̷ adjective
Etymology: under (II) + sea, n.
1. : being or carried on under the sea or under the surface of the sea
undersea oil deposits
undersea fighting
2. : designed for use under the surface of the sea
undersea fleet
undersea cable
II. adverb
or underseas | ̷ ̷ ̷ ̷| ̷ ̷
Etymology: under (II) + sea, n. or seas, plural of sea, n.
: under the sea : beneath the surface of the sea
photographs taken undersea