Would he make a woolly-headed friend? (5)
I believe the answer is:
wally
'would he' is the definition.
The definition suggests a singular noun which matches the answer.
'a woolly-headed friend?' is the wordplay.
'a woolly-headed' becomes 'w' (this could be a standard abbreviation I've not previously seen).
'friend?' becomes 'ally' (an ally is a friend or supporter).
'w'+'ally'='WALLY'
'make' acts as a link.
Can you help me to learn more?
(Other definitions for wally that I've seen before include "Idiot (slang)" , "Complete idiot" , "A fool (sl.)" .)