This burn in Dumbarton arises from the confluence of the Garshake and Overtoun Burns. In the past, some have linked its name to Bishop William Scroggie, but it is far more likely that it takes its name from the Grugie family who, in the 17th century, lived near the point where the turnpike road (on the line of what is now Dumbarton Road) crossed the burn by means of a bridge that was shown as "Grugiesbrigg" on Roy's Military Survey; the family name is now associated with the burn as a whole. Quoted from the Geograph website.