Rearrest posh criminal who keeps money (9)
I believe the answer is:
treasurer
'keeps money' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
'rearrest posh criminal' is the wordplay.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'criminal' indicates an anagram.
'rearrest'+'u'='rearrestu'
'rearrestu' is an anagram of 'TREASURER'.
'who' is the link.
Can you help me to learn more?
(Other definitions for treasurer that I've seen before include "who's got hold of the cash?" , "position in society?" , "Committee member" , "Society official" , "He handles the money for an organisation" .)