2. DETERMINATE NUMBER
two, deuce, couple, duet, brace, pair, cheeks, twins, Castor and Pollux, gemini, Siamese twins; fellows; yoke, conjugation; dispermy, doublets, dyad, span.
[Adjectives] two, twin; dual, dualistic, double; binary, binomial; twin, biparous; dyadic; conduplicate; duplex [more]; biduous, binate, diphyletic, dispermic, unijugate; tete-a-tete.
both, both the one and the other.