Euclid, city, Cuyahoga county, northeastern Ohio, U.S., on Lake Erie, just northeast of Cleveland. The original township area was settled in 1797 and was named for the famous Greek mathematician by the surveyors who arrived with Moses Cleaveland, an agent of the Connecticut Land Company. It remained largely rural, noted chiefly for grapes, until after 1940, when there was rapid industrial and urban growth. Manufactures now include airplane parts, assembly-line equipment, motors, metal fasteners, electrical and welding equipment, and earthmovers. Inc. village, 1903; city, 1930. Pop. (2000) 52,717; (2010) 48,920.