undersea

Definition

Existing, relating to, or made for use beneath the sea.

Etymology

From under- + sea.

Example Sentences

• "It is not known just what action will be taken against the captain of the undersea boat."
• ""You're right!" she cried. "I'm sure you are." Twenty reasons come back. An undersea tunnel to the little island."
• "The Sediment (SNAP-7E) Density Meter (an underwater rocket) has been developed to investigate to an ocean-bottom depth of 11 sedimentary feet. Sea Lab I, the Navy’s new undersea laboratory, complete with observation porch and garage, should become safe to operate at the 200 foot level."