sea level

American  

noun

• sea levels
  plural

1. the horizontal plane or level corresponding to the surface of the sea at mean level between high and low tide.

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sea level British  

noun

1. the level of the surface of the sea with respect to the land, taken to be the mean level between high and low tide, and used as a standard base for measuring heights and depths

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sea level Scientific  

1. The level of the ocean's surface. Sea level at a particular location changes regularly with the tides and irregularly due to conditions such as wind and currents. Other factors that contribute to such fluctuation include water temperature and salinity, air pressure, seasonal changes, the amount of stream runoff, and the amount of water that is stored as ice or snow.

2. ◆ The reference point used as a standard for determining terrestrial and atmospheric elevation or ocean depths is called the mean sea level and is calculated as the average of hourly tide levels measured by mechanical tide gauges over extended periods of time.

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Other Word Forms

Noun Inflected Forms

• sea levels
  plural

Etymology

Origin of sea level

First recorded in 1800–10

Example Sentences

See Examples For:

sea level

A rare convergence of a powerful El Niño, super king tides and sea level rise spurred by climate change could menace California with record coastal flooding this winter.

From Los Angeles Times ● Aug. 24, 2026

The change in elevation from the waterfront at sea level to Genoa’s mountainous hinterland approaches 6,000 feet, and variations between adjoining neighborhoods can be as much as several hundred feet.

From The Wall Street Journal ● Aug. 23, 2026

Now their country, which is lower than sea level, finds itself, in an era of global warming, facing a dilemma: how to retain water while protecting themselves from it?

From Barron's ● Aug. 15, 2026

Many of the bodies, like Morup's, are in what climbers call Everest's death zone – where temperatures can plunge to -40C and oxygen levels are about a third of those at sea level.

From BBC ● Aug. 8, 2026

His head was pounding, and he wasn’t sure if it was from stress or the altitude—Santa Fe is over 7,000 feet above sea level.

From "Bomb" by Steve Sheinkin

Related Words

• water level