Wikipedia
Gaughan
The surname Gaughan is derived from the Old Gaelic name Ua Gáibhtheacháin, which dates to before the 10th century. Its meaning is "male descendant of a fierce warrior". However, other translations claim it means "anxious one", demonstrating their expeditious and industrious nature. Historically, Irish families were named after the first chief of their tribe. In this case, it is evident that this clan descends from an illustrious warrior. Other derivatives of Ua Gáibhtheacháin are: O'Gaughan, Gavan, Gavaghan, Gavahan, Gavigan and Gahan.
As Old Ireland evolved, the surname O'Gáibtheacháin was shortened to O'Gacháin. This name was later anglicized into Gaughan.