Finance man's rearrest with posh criminal (9)
I believe the answer is:
treasurer
'finance man's' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.
'rearrest with posh criminal' is the wordplay.
'with' means one lot of letters go next to another.
'posh' becomes 'u' (abbreviation for upper-class - opposite to non-U).
'criminal' indicates an anagram.
'rearrest'+'u'='rearrestu'
'rearrestu' is an anagram of 'TREASURER'.
Can you help me to learn more?
(Other definitions for treasurer that I've seen before include "Financial controller" , "Financial officer" , "he's got the money" , "Fund manager" , "Society official" .)