Charlie lacks refinement and is vulgar (5)
I believe the answer is:
crude
'is vulgar' is the definition.
(synonyms)
'charlie lacks refinement' is the wordplay.
'charlie' becomes 'C' (phonetic alphabet).
'lacks refinement' becomes 'rude' (I can't justify this - if you can you should believe this answer much more).
'c'+'rude'='CRUDE'
'and' acts as a link.
Can you help me to learn more?
(Other definitions for crude that I've seen before include "Primitive; oil" , "Raw, immature" , "Natural mineral oil" , "In a natural state - vulgar" , "foul-mouthed?" .)