Under the surface of the sea or ocean, underwater.

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

Lacking sufficient seasoning.

Third-person singular simple present indicative form of underseal

plural of underseal

A thick, resilient coating applied to the underbody or chassis of an automobile to protect against damage from small stones, etc, which would rapidly chip ordinary paint and allowing rusting to begin.

(transitive) To coat (the underbody or chassis of a vehicle) with underseal.

simple past tense and past participle of underseal

present participle of underseal

Located under a seat (typically as a fixed part of the overall structure of the vehicle).