Trophonian \Tro*pho"ni*an\, a. [L. Trophonianus, fr. Trophonius, Gr. ?, a Grecian architect, fabled to have been the builder of the first temple of Apollo at Delphi. He was worshiped after death, and had a celebrated oracle in a cave in B[oe]otia.] Of or pertaining to Trophonius, his architecture, or his cave and oracle. [1913 Webster]