As described in historical dictionaries

An Etymological Dictionary of Family and Christian Names (1857)

Said to be derived from one Scirrard, who came with William the Conqueror, and obtained lands in Chester and Lancaster, England. As a local name, it may signify in Anglo Saxon, a high cliff; rocky heights, from Scearard.

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


Patronymica Britannica (1860)

SHERARD. SHERRARD. " Our

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


BritishSurnames.uk is a Good Stuff website.