An Etymological Dictionary of Astronomy and Astrophysics

1. General: Pertaining to, established by, or conforming to a canon, i.e. a law or a general rule (especially in ecclesiastical matters).
   
2. Math.: Relating to the simplest or standard form of a general function, equation, rule, etc.

Etymology (EN): M.M. canonicalis, from canonic(us), from L. canon, from Gk. kanon “a straight rod, a measuring rod, rule " + alis, → -al.

Etymology (PE): Hanjârvâr, from hanjâr “a mason’s rule, any string or instrument used by builders in laying stones straight; rule, law, way, custom; a norm” + -vâr suffix meaning “having, endowed with; like, in the manner of.”