Excessively fast (like some New Testament swine?) — a grandee (anag) (8)
I believe the answer is:
gadarene
(Other definitions for gadarene that I've seen before include "Rushing disastrously" , "Suicidal animals (in the Bible)?" , "The - swine rushed into the sea (Bible)" , "Biblical swine that ran into sea possessed by devils" , "Rushing headlong, like the Biblical swine" .)