Lower, Mark A (1860) Patronymica Britannica: a dictionary of the family names of the United Kingdom. London: J.R. Smith. Public Domain.
FENNING
As described in historical dictionaries
Patronymica Britannica (1860)
FENNING. May be local, but I do not find the place. I think it may possiblj' be a Scandinavian personal name, and the genitive form, Fennings, rather confirms this view.