Where does “non compos mentis” come from?

non compos mentis (English) comes from Latin nōn, from Old Latin noenum, from Proto-Indo-European óynos — one; single.

non compos mentis (English): Insane; not of sound mind; not in control of...

Definitions

  1. Insane; not of sound mind; not in control of...

Ancestry of “non compos mentis”, step by step

StepLanguageWordMeaning
1Latinnōnnot
2Old Latinnoenum—
3Proto-Indo-Europeanóynosone; single

Words derived from “non compos mentis”

Every word from Proto-Indo-European óynos →Every word from Old Latin noenum →Every word from Latin nōn →