(nautical) A (dangerous) sea with two wave systems traveling at oblique angles, due to the wind over it shifting direction or the waves of two storm systems meeting.

(geography) An alternative name of the Caspian Sea.

Alternative spelling of seawall

A large jellyfish, Cyanea capillata.

The deeper part of the sea or ocean in which no light penetrates / (sport fishing) open sea (part of the sea out of sight of land)

Of, related to or located in the deeper part of the sea. / (sport fishing) Of or related to open sea. / (of a port) Able to accommodate the largest ships.

A coastal town in Essex, England, United Kingdom, on the Thames estuary / A unitary authority with borough status in Essex.

The oceans of the earth at a time early in its history. The term generally implies either the time before or during the development of multi-cellular life forms (i.e., during the Precambrian), or alternatively before the development of the first land-based life forms (i.e. during the early Paleozoic).

(Britain, colloquial, archaic) A herring. / (literally) One who roams about the ocean much of the time. / A pirate, buccaneer or privateer; an ocean-going marauder.

Alternative spelling of seabed