Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
PET
As described in historical dictionaries
Patronymica Britannica (1860)
tifM" PET. A provincial corruption of 7;ii ; and hence, probably, the true forms of such surnames as Pethurst, Petford, Petley, would be Pithurst, Pitford, Pitley.