Charlie, more fashionable and cheerful (7)
I believe the answer is:
chipper
'cheerful' is the definition.
(similar in meaning)
'charlie more fashionable' is the wordplay.
'charlie' becomes 'C' (phonetic alphabet).
'more fashionable' becomes 'hipper' (hip can mean fashionable or trendy).
'c'+'hipper'='CHIPPER'
'and' acts as a link.
(Other definitions for chipper that I've seen before include "person damaging crockery?" , "Briskly cheerful" , "Smart" , "worker in fast-food outlet?" , "golfer, perhaps?" .)