Emily Dickinson Lexicon

DI-CHOT'O-MY, n. [Gr. διχοτομια, a division into two parts; διχα and τεμνω, to cut.]

1. Division or distribution of ideas by pairs. [Little used.] – Watts.
2. In astronomy, that phase of the moon in which it appears bisected, or shows only half its disk, as at the quadratures. – Encyc.