Simon's son Robert was called Boyt or Boyd from the Celtic term boidhe, meaning fair or yellow.

[1] The Scottish peerage of the earls of Kilmarnock ends shortly after William Boyd rebelled in the Battle of Culloden in 1746.

He left a widow and three sons including James, Lord Boyd who married and succeeded his father as the Earl of Errol, taking his mother's title.

[2] Another theory is of territorial origins which may have been taken from the Bhoid, the Gaelic term for the island of Bute,[3] in the Firth of Clyde.

[4] The Scottish Gaelic form of the surname is Boid (masculine),[5] and Bhoid (feminine).