sea level
Concise Oxford English Dictionary © 2008 Oxford University Press:
sea level
▶noun the level of the sea's surface, used in reckoning the height of geographical features and as a barometric standard.
'sea level' also found in these Oxford entries:
altitude
- atmosphere
- contour
- elevation
- eustasy
- geoid
- height
- high
- hypsometer
- low-lying
- mean sea level
- ordnance datum

