Webster's Revised Unabridged Dictionary · 1913

Euclidian

Euclidian , noun

Related to Euclid, or to the geometry of Euclid.
Collocations (1)
Euclidian space (Geometry) , the kind of space to which the axioms and definitions of Euclid, relative to straight lines and parallel lines, apply; -- called also flat space, and homaloidal space.