word-forming element meaning "equal, similar, identical; isometric," from comb. form of Greek isos "equal to, the same as" (e.g. isometor "like one's mother"). Used properly only with words of Greek origin; the Latin equivalent is equi- (see equi-).
iso- or is-
Equal; uniform: isobar.
Characterized by sameness with respect to species: isoantigen.
Characterized by sameness with respect to genotype: isograft.