trichotomy

Meaning

Noun

• Division or separation into three groups or pieces.
• the property of an order relation whereby, given an ordered pair of elements (of a given algebraic structure), exactly one of these is true: the first element is 'less than' the second one, the second is 'less than' the first, or the two elements are equal.

Origin

• tri-; formed analogously from dichotomy as if it were from di- + -chotomy.