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.

---

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

---

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.

---

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

Adding to the logistical pressure, a landslip in June closed off part of the track to the tiny village at the top of the island about 400ft above sea level.

From BBC ● Oct. 7, 2026

The sea level is rising at a record pace, driven by warming oceans and glacier melt, according to a UN report.

From Barron's ● Oct. 2, 2026

By redistributing enormous amounts of heat through the Atlantic, it helps shape regional temperatures, rainfall patterns, sea level, and weather.

From Science Daily ● Sep. 23, 2026

The Panama Canal relies on rainwater for its complex system of locks, which lifts ships almost 90 feet above sea level onto a navigable waterway, and then lowers them at the other end.

From The Wall Street Journal ● Sep. 23, 2026

So wand in hand he paced into the air, shot from Pieria down, down to sea level, and veered to skim the swell.

From "The Odyssey" by Homer

Related Words

• water level