Non Compos Mentis - "Not mentally competent" or "Not of sound mind" Hot Latin T-shirts, bumper stickers, mugs, posters, more. Cool & useful gifts for teachers & lovers of Latin & the classics.in Latin. Learn Latin! Teach Latin! Love Latin! Here are the best gifts for teachers and lovers of Latin and the classics: t-shirts, mugs, posters, prints, mousepads, note cards, & more!