Definition of "Mungo"

The fever left his body, and he rose to stotter about the doors; but he was still in his torments, and the mercy-seat was far from him. At last in the back end of the year came Mungo Muirhead to Caulds to the autumn communion, and nothing would serve him but he must try his hand at the storm-tossed soul.

1902, John Buchan, The Outgoing of the Tide