Penny is after china mug (5)
I believe the answer is:
chump
'mug' is the definition.
(synonyms)
'penny is after china' is the wordplay.
'penny' becomes 'p'.
'is after' says to put letters next to each other.
'china' becomes 'chum' (china [plate] is Cockney rhyming slang for mate).
'p' after 'chum' is 'CHUMP'.
(Other definitions for chump that I've seen before
include
"Thick