Crafty, underhand (6)
I believe the answer is:
sneaky
This clue is a double definition.
'crafty' is the first definition.
(thesaurus)
'underhand' is the second definition.
(I know that underhand can be written as sneaky)
(Other definitions for sneaky that I've seen before include "Deceitful, underhand" , "Furtive or given to telling tales" , "Secretive and sly" , "Furtive, underhand" , "Sly and devious" .)