Clever start for Sylvester? (3)
I believe the answer is:
sly
'clever' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for sly that I've seen before include "Sneaky" , "Wily, shifty" , "Artful" , "Unpleasantly cunning and secretive" , "Devious, cunning" .)