1660s, "of, pertaining to, or resembling the Greek god Apollo," from Apollo (Greek Apollon) + -ian. The Greek adjective was Apollonios. Other adjectival forms in English include Apollinarian, Apollonic, Apolline (c. 1600). Also sometimes in reference to Apollonius of Perga, the great geometer.
apodictic
apodyterium
apogee
apolitical
Apollo
Apollonian
Apollyon
apologetic
apologetics
apologia
apological