Growing in two parts or in pairs.

Roget 89: two, twin; dual, dualistic, double; binary, binomial; twin, biparous^†; dyadic [Math.]; conduplicate^†; duplex etc. 90; biduous^†, binate^†, diphyletic^†, dispermic^†, unijugate^†; tete-a-tete.    coupled etc. v.; conjugate.    both, both the one and the other.    ... meer laten zien