quad·riv·i·um 
(kwŏ-drĭvē-əm)
(kwŏ-drĭvē-əm)n. pl. quad·riv·i·a (-ē-ə)
The higher division of the seven liberal arts in the Middle Ages, composed of geometry, astronomy, arithmetic, and music.
[Late Latin, from Latin, place where four roads meet : quadri-, quadri- + via, road; see VIA.]