Euclid2Pronunciation: /ˈjuːklɪd/Definition of Euclid (circa 300 bc), Greek mathematician. His great work Elements of Geometry, which covered plane geometry, the theory of numbers, irrationals, and solid geometry, was the standard work until other kinds of geometry were discovered in the 19th century. Euclid in other Oxford dictionaries Definition of Euclid in the US English dictionary
