Funnier when that ruddy hairstyle's receding (5)
I believe the answer is:
odder
'funnier when' is the definition.
I can't judge whether this defines the answer.
'ruddy hairstyle's receding' is the wordplay.
'ruddy' becomes 'red' (synonyms).
'hairstyle' becomes 'do' (a hairdo).
'receding' says the letters should be written backwards.
'red'+'do'='reddo'
'reddo' written backwards gives 'ODDER'.
'that' is the link.
Can you help me to learn more?
(Other definitions for odder that I've seen before include "More unusual" , "More strange or less even" , "more rum" , "More peculiar" , "Stranger" .)