adj.1 a having the same relation, relative position, etc. b corresponding.
2 Biol. (of organs etc.) similar in position and structure but not necessarily in function.
3 Biol. (of chromosomes) pairing at meiosis and having the same structural features and pattern of genes.
4 Chem. (of a series of chemical compounds) having the same functional group but differing in composition by a fixed group of atoms.
Etymology: med.L homologus f. Gk (as HOMO-, logos ratio, proportion)