Deer also known as wapiti (3)
I believe the answer is:
elk
'deer also known as wapiti' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for elk that I've seen before include "Moose-like deer" , "Fraternal American" , "Wapiti" , "European moose" , "Big deer" .)