Synonyms and related words :
Janus-like, ambidextrous, bifacial, bifold, biform, bifurcated, bilateral, binary, binate, biparous, bipartisan, bipartite, bivalent, conduplicate, dichotomous, disomatous, double, double-barreled, double-faced, duadic, dualistic, duple, duplex, duplicate, duplicated, dyadic, geminate, geminated, identical, matched, paired, second, secondary, twain, twin, twinned, two, two-faced, two-level, two-ply, two-sided, two-story, twofold