Lewis & Short

Trŏphōnĭus, ii, m., = Τροφώνιος.

  1. I. A brother of Agamedes, in conjunction with whom he built the temple of Apollo at Delphi, Cic. Tusc. 1, 47, 114.
  2. II. A deity that imparted oracles in a cave near Lebadia, in Bœotia; sometimes called also Juppiter Trophonius, Cic. Div. 1, 34, 74; id. N. D. 3, 19, 49; Liv. 45, 27, 8; Plin. 34, 8, 19, § 66; 31, 2, 11, § 15.
    Hence, Trŏphōnĭānus, a, um, adj., of or belonging to Trophonius, Trophonian: narratio Chaeronis, of a certain Chœron, who descended into Trophonius’s cave, Cic. Att. 6, 2, 3.