Oisin \o(i)-sin\ as a boy's name is pronounced OH-sheen. It is of Gaelic origin. In Irish history, the name of the son of a legendary Gaelic poet, Fionn mac Cumhaill. Oisin mac Cumhaill was a warrior and bard too. The anglicized form Ossian was revived in the 18th century by Jasmes Macpherson as the name of the supposed author of some ancient Gaelic poetry which Macpherson claimed to have translated. It turned out that Macpherson had written much of the poetry himself.