Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
GRISELL
As described in historical dictionaries
Patronymica Britannica (1860)
GRISELL. GRISSELL. A Saint Grizelda or Grizel occurs in Scotland, though omitted by Camerarius in his list of Scottish saints. Chambers' Pop. Rhymes of Scotland. A less complimentary derivation would be from grisrl, the diminutive of the A-Norm. grls, .a pig. So we have the vernacular Pigg, Wildbore, and other analogous surnames. See Purcell.