sea level

sea level

noun

: the average height of the sea's surface

Full Definition of SEA LEVEL

:  the level of the surface of the sea especially at its mean position midway between mean high and low water

First Known Use of SEA LEVEL

1806

Rhymes with SEA LEVEL

A level, bedevil, bi-level, daredevil, dishevel, dust devil, go-devil, high-level, low-level, O level, S level, split-level

sea level

noun    (Concise Encyclopedia)

Position of the air-sea boundary, to which all terrestrial elevations and submarine depths are referred. The sea level at any location changes constantly with changes in tides, atmospheric pressure, and wind conditions. Longer-term changes are influenced by changes in the Earth's climates. Consequently, the level is better defined as mean sea level, the height of the sea surface averaged over all stages of the tide over a long period of time.