Perverts dance on Sabbath (6)
I believe the answer is:
twists
'perverts' is the definition.
(I know this)
'dance on sabbath' is the wordplay.
'dance' becomes 'twist' (type of dance).
'on' says to put letters next to each other (in a down clue, letters appear on others).
'sabbath' becomes 's'.
'twist'+'s'='TWISTS'
(Other definitions for twists that I've seen before include "Coils around something or dances vigorously" , "Interweaves or gives spiral form to" , "Wrenches round" , "Bends and turns out of shape" , "Dances and turns as Chubby Checker used to" .)