Outdoes (6)
'outdoes' is the definition.
('best' can be a synonym of 'outdo')
This is all the clue.
(Another definition for bests that I've seen is " Worsts".)
(Other definitions for excels that I've seen before include "Does better than, is really very good" , "Surpasses" , "does best" , "Performs exceptionally well" , "Does very well, outshines" .)
'outdoes' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tops that I've seen before include "The Four -, Motown group" , "spinners" , "Caps; outdoes" , "Upper garments" , "Does better" .)