Dictionary.net

A name given in the Ossianic poetry to a semi-mythical class of warriors of superhuman size, strength, speed and prowess. Generally they are supposed to have been a sort of Irish militia, and to have had their name from Fion Mac Cumbal (the Finn Mac Coul of Dunbar, and Fingal of Macpherson), their most distinguished leader; but Mr. Skene believes them to have been of the race that inhabited Germany before the Germans, and Scotland and Ireland before the Scots.