Definition

A horizontal plane or line; especially, such a plane taken as a basis for the measurement of ELEVATI­ON. See SEA LEVEL, MEAN SEA LEVEL, HALF TIDE LEVEL, STILL WATER LEVEL. A level tract of land; a stretch of country ap­proxi­mately horizontal and unbroken by ELEVATIONS. In SURVEYING and LEVELLING, either a SPIRIT LEVEL or a LEVELLING INSTRUMENT.