Trivium

·noun The three anterior ambulacra of echinoderms, collectively.

II. Trivium ·noun The three " liberal" arts, grammar, logic, and rhetoric;

— being a triple way, as it were, to eloquence.

trivium
trĭvĭum, i, n. [ter-via]. I Lit., a place where three roads meet , a fork in the roads , cross-r...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
trivium
trivium ī, n ter+via, a place where three roads meet, fork, cross-road : ut ventum est in trivium....

An Elementary Latin Dictionary