Di*chot"o*my (?), n. [Gr. &?;, fr. &?;:
cf. F. dichotomie. See Dichotomous.] 1.
A cutting in two; a division.
A general breach or dichotomy with their
church. Sir T. Browne.
2. Division or distribution of genera into
two species; division into two subordinate parts.
3. (Astron.) That phase of the moon in
which it appears bisected, or shows only half its disk, as at the
4. (Biol.) Successive division and
subdivision, as of a stem of a plant or a vein of the body, into two
parts as it proceeds from its origin; successive
5. The place where a stem or vein is
6. (Logic) Division into two;
especially, the division of a class into two subclasses opposed to
each other by contradiction, as the division of the term man
into white and not white.