Vaughan and Vaughn are surnames, originally Welsh, though also used as a form of the Irish surname McMahon.
[1] Vaughan derives from the Welsh word bychan, meaning "small", and so corresponds to the English name Little and the Breton cognate Bihan.
The word mutates to Fychan (Welsh: [ˈvəχan]) an identifier for a younger sibling or next of kin.
It can also be used as a first name Vaughan (given name).