Deal with prohibition on moustache (9)
I believe the answer is:
handlebar
'moustache' is the definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'deal with prohibition' is the wordplay.
'deal with' becomes 'handle' (synonyms).
'prohibition' becomes 'bar' (I can't explain this - if you can you should believe this answer much more).
'handle'+'bar'='HANDLEBAR'
'on' acts as a link.
Can you help me to learn more?
(Other definitions for handlebar that I've seen before include ""Support for the cyclist"" , "Whiskers?" , "Moustache like one on a bicycle" , "part for rider to grip" , "Upwardly curled facial growth" .)