Sharper and more cunning following ace (6)
I believe the answer is:
acuter
'sharper' is the definition.
('acute' can be a synonym of 'sharp')
'more cunning following ace' is the wordplay.
'more cunning' becomes 'cuter' ('cute' can be a synonym of 'cunning').
'following' means one lot of letters go next to another.
'ace' becomes 'a'.
'cuter' after 'a' is 'ACUTER'.
'and' is the link.
(Other definitions for acuter that I've seen before include "More sharp or shrewd" , "Sharper" .)