Cleverly effective (4)
I believe the answer is:
neat
'cleverly effective' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for neat that I've seen before include "Tidy - old cow!" , "well-kept" , "Shipshape" , "Tidy, well-ordered" , "Tidy - orderly" .)