Mac Thréinfhir
Mac THRÉINFHIR—IV—M'Crenir, M'Kreaner, MacCreanor, MacCranor, MacCrainor, Treanor, Trenor, Trayner, Trainor, Traynor, Tranor; 'son of Tréanfhear' (an Irish personal name, meaning 'champion,' literally, 'strong-man'); a well-known Ulster surname.
Alphabetical Index to Irish Surnames