What is another word for "counterpart"?

Roget's Thesaurus (1911) lists these synonyms for "counterpart": against, and, antarctic, antipodal, antipodes, antonym, arctic, asunder, contraposition, contrariety, converse, diametrically, face, facing, inverse, inversion, opposite, opposition, over, polarity, reverse, septentrional, side, subcontrary, subtend, the, vis, way.