Smart superior wanting introduction (5)
I believe the answer is:
nobby
'smart' is the definition.
(thesaurus)
'superior wanting introduction' is the wordplay.
I cannot quite understand how this works, but
'wanting' could be 'no' (to want is to lack or have none of something) and 'no' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for nobby that I've seen before include "Mr Clark(e)" , "Toff" .)