Some ancient writers say, that Robert, son of David, Earl of Huntingdon, took on him the cross, and distinguished himself in the Holy Land, where, from his gallant exploits against the Saracens, he received the name of Guishart, that is, Wise-heart, now Wishart.

Arthur, William (1857) An Etymological Dictionary of Family and Christian Names. New York: Sheldon, Blakeman. Public Domain.

WISHART. Perhaps the old personal name Guiscard. This seems likely, from the mediate form Wiscard in H.R.

Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.