Eastern light reveals antelope (5)
I believe the answer is:
eland
'antelope' is the definition.
(eland is a kind of antelope)
'eastern light' is the wordplay.
'eastern' becomes 'e'.
'light' becomes 'land' (light can mean to settle or land).
'e'+'land'='ELAND'
'reveals' is the link.
(Other definitions for eland that I've seen before include "Led an (anag) -- antelope" , "wild creature" , "Browser" , "game animal" , "Antelope seen by Africans" .)