Webster's Revised Unabridged Dictionary · 1913

Trivium

Trivium , noun

[Late Latin See Trivial.]

1.
The three “ liberal” arts, grammar, logic, and rhetoric; -- being a triple way, as it were, to eloquence.

The trivium and quadrivium together made up the seven liberal arts. See Quadrivium.

2.
(Zoology) The three anterior ambulacra of echinoderms, collectively.