Deep-sea /(?)/

Deep·-sea

Deep-sea

a.
  1. Of or pertaining to the deeper parts of the sea; as, a deep-sea line (i. e., a line to take soundings at a great depth); deep-sea lead; deep-sea soundings, explorations, etc.
  2. at some distance from the shore; as, deep-sea fishing.
  3. taking place in the deeper parts of the sea; as, deep-sea exploration.