The Oxford Dictionary:
Definition of dichotomy
noun (plural dichotomies)
[usually in singular]
a division or contrast between two things that are or are represented as being opposed or entirely different: a rigid dichotomy between science and mysticism
Botany repeated branching into two equal parts.
Origin:
late 16th century: via modern Latin from Greek
dikhotomia, from
dikho- 'in two, apart' +
-tomia (see -tomy)
