Crude set-up engenders hostilities (3)
I believe the answer is:
war
'hostilities' is the definition.
(hostilities between two nations)
'crude set-up' is the wordplay.
'crude' becomes 'raw' (synonyms).
'set up' is a reversal indicator (in a down clue, letters go up).
'raw' back-to-front is 'WAR'.
'engenders' acts as a link.
This may not be right. It may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for war that I've seen before include "State of armed struggle" , "Combat" , "Large-scale conflict" , "Sustained conflict" , "Hostile situation" .)