Homaloid \Hom"a*loid\ (h[o^]m"[.a]*loid), Homaloidal \Hom`a*loid"al\ (-loid"al), a. [Gr. "omalo`s even + -oid.] (Geom.) Flat; even; -- a term applied to surfaces and to spaces, whether real or imagined, in which the definitions, axioms, and postulates of Euclid respecting parallel straight lines are assumed to hold true.