dichotomy

1. A separation or division into two; a distinction that results in such a division. (countable, uncountable)
2. Such a division involving apparently incompatible or opposite principles; a duality. (countable, uncountable)
3. The division of a class into two disjoint subclasses that are together comprehensive, as the division of human into female and male. (countable, uncountable)
4. The division of a genus into two species; a division into two subordinate parts. (countable, uncountable)
5. A phase of the moon when it appears half lit and half dark, for example at the quadratures. (countable, uncountable)
6. Division and subdivision; bifurcation, such as that of a stem of a plant or a vein of the body into two parts as it proceeds from its origin; often successive. (countable, uncountable)

Plural dichotomies