Traynor, Treanor, Trainor, Mac Thréinfhir A Gaelic surname derived from Tréanfhear meaning ‘strong-man’. A sept of Oriel In Scotland the surname has been recorded in Fife. There is an English surname Trainer derived from the Middle English trayne meaning to ‘set a trap’, a reference to a trapper. In 1890 Traynor was principally found in Dublin, Treanor and Trainor in Antrim, Armagh, Monaghan and Tyrone, and the estimated number of bearers was 3,450 (all variants). In the United States Traynor is the 8,158th most numerous surname with an estimated 2,750 bearers, and Trainor is the 5,141st most numerous surname with an estimated 5,500 bearers.