Long-horned antelope (4)
I believe the answer is:
oryx
'long-horned antelope' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for oryx that I've seen before include "African native" , "African long-horned grazer" , "Large African antelope with long straight horns" , "horny beast" , "Animal" .)