Trophonian UK /tɹəˈfəʊ.ni.ən/US /tɹəˈfoʊ.ni.ən/ adjective1 •Of or pertaining to Trophonius, a mythological figure of Ancient Greece, said to have built the temple of Apollo at Delphi and the treasury of King Hyrieus in Boeotia. formsmore Trophonian · most Trophonian