"of, pertaining to, or of the nature of mathematics," early 15c., from Medieval Latin mathematicus "of or belonging to mathematics," from Latin mathematica (see mathematic) + -al (1). Also, by 1765, "pertaining to the quadrivium," comprising arithmetic, geometry, astronomy, and music. It also could include optics. Related: Mathematically.
The four mathematical arts are arithmetic, geometry, music, and astronomy; these anciently were termed the quadrivium, or fourfold way of knowledge. [Sir John Hawkins, "A General History of the Science and Practice of Music," Sir John Hawkins, 1776]