Pig-headed associate, but not unfriendly (5)
I believe the answer is:
pally
'not unfriendly' is the definition.
I can't judge whether this defines the answer.
'pig-headed associate' is the wordplay.
'pig-headed' becomes 'p' (start (head) of the word pig).
'associate' becomes 'ally' (ally is a kind of associate).
'p'+'ally'='PALLY'
'but' acts as a link.
Can you help me to learn more?
(Other definitions for pally that I've seen before include "Intimate" , "On friendly terms" , "China may be so" , "Very familiar" , "Chummy" .)