-_mē noun
( -es )
Etymology: probably from (assumed) New Latin trichotomia, from Greek trichotomein to trisect (from tricha threefold — akin to Greek treis three — + temnein to cut) + Latin -ia -y — more at three , tome
1. : a dividing into three parts, elements, or classes
the trichotomy of speech-sciences into phonetics, phonemics, and historical phonetics — R.S.Wells
— compare polytomy
2. : a system divided or divisible into three constituents or elements
to speak of man as a trichotomy , … having a division into three parts — Gottfried de Purucker