Antelope can't stand crossing river, most advantageous to traverse end of June (10)
I believe the answer is:
hartebeest
'antelope' is the definition.
(hartebeest is a kind of antelope)
'can't stand crossing river most advantageous to traverse end of june' is the wordplay.
I cannot quite see how this works, but
'river' could be 'r' (abbreviation for river) and 'r' is located in the answer.
'can't stand' could be 'hate' (if you hate something you can't stand it) and 'hate' is present in the remaining letters.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for hartebeest that I've seen before include "Creature" , "African native" , "antelope" , "wild animal" , "Game" .)