North American bison (7)
I believe the answer is:
buffalo
'north american bison' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for buffalo that I've seen before include "Colloquialism for the N American bison" , "Great Lakes port" , "Large bovine animal" , "Large animal of the cattle family" , "Ox with swept-back horns" .)