(n.) The four "liberal arts," arithmetic, music, geometry, and astronomy; -- so called by the schoolmen. See Trivium.
Example Sentences:
(1) In medieval times, music was part of the quadrivium, studied alongside maths, geometry and astronomy.
(2) This Pythagorean view re-emerged in medieval universities, where scholars studied the quadrivium, which divided the science of mathematics into four parts: geometry and arithmetic, astronomy and music.
Trivium
Definition:
(n.) The three " liberal" arts, grammar, logic, and rhetoric; -- being a triple way, as it were, to eloquence.
(n.) The three anterior ambulacra of echinoderms, collectively.