Deftness in a sense (5)
I believe the answer is:
touch
This clue is a double definition.
'deftness' is the first definition.
(I know that touch is a type of deftness)
'sense' is the second definition.
(I know that touch is a sense)
'in a' acts as a link.
(Other definitions for touch that I've seen before include "To ask for loan" , "Hint" , "Side beyond playing area" , "Come into contact with" , "Manner of playing piano, say" .)