This name means "strong man, masculinity, a man of vigor." The name derives from the Old Irish name “Fearghus / Fearghas,” composed of two elements: “fer / fear” (man) plus “gus” (force, wildness, pride, courage, determination, initiative, self-esteem). Fergus or Feargus is a popular Irish, Manx, and Scottish given name. It is both the Old Irish spelling and the anglicized form of the modern Fearghus or Fearghas, meaning "man-strength" or "virility." The name Fergus was a royal name amongst the Celts in Ireland and the Picts in Scotland. Although a relatively rare name, it is still prevalent among the Scottish nobility and gentry. No fewer than three current Clan Chiefs are named Fergus. Saint Fergus (Fergustian) († 730 AD) was a bishop who worked in Scotland as a missionary. Ten saints of this name are mentioned in the martyrology of Donegal.