Clobber worn by sub playing okay (6-2)
I believe the answer is:
thumbs-up
'okay' is the definition.
(I've seen this before)
'clobber worn by sub playing' is the wordplay.
'clobber' becomes 'thump' (I've seen this before).
'worn by' is an insertion indicator (outside letters are worn by those on the inside).
'playing' indicates anagramming the letters.
'sub' with letters rearranged gives 'bsu'.
'thump' going around 'bsu' is 'THUMBS-UP'.
(Other definitions for thumbs-up that I've seen before include "Elevated digits as sign of approval" , "Digital sign of approval as in Roman Colosseum" , "Approving sign" , "Sign of success" , "Old Roman sign for mercy, with elevated digits" .)