Fergus

Fergus is a popular Irish, Manx and Scottish name which anglicises Fearghas meaning "man-strength" or "virility". Derived from the Gaelic "fear-ghur" the name Fergus was a royal name amongst the Celts in Ireland and the Picts. Fergus mac Erc is reputed to have led the Scots from northern Ireland to the west coast of Scotland to establish the kingdom of Dalriada. The second Abbot of Iona was Fergus Brit (605-623AD). Followers of Fergus, Lord of Galloway, fought at the Battle of the Standard (1138). His descendants became the earls of Carrick. As a surname, MacFergus evolved into Ferguson/Fergusson and this surname spread across Scotland but particularly in Ayrshire and Perthshire. Other forms of Fergus include Fearghas, Fearghus and Feargus.
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[Celtic] The Celtic/Irish hero and king, one of the warlike lovers of queen Medb. Fergus ("virility") is also referred to as "the great horse", and many (phallic) marvels are ascribed to him.