By jumping tear trousers more (5)
I believe the answer is:
extra
'more' is the definition.
(I've seen this in another clue)
'by jumping tear trousers' is the wordplay.
'by' becomes 'x' (2 by 4 is 2 x 4).
'jumping' indicates anagramming the letters.
'trousers' indicates putting letters inside (trouser can mean to steal or take).
'tear' with letters rearranged gives 'etra'.
'x' put within 'etra' is 'EXTRA'.
(Other definitions for extra that I've seen before include "Possibly a bad ball" , "score (not a hit)" , "someone in a crowd scene" , "Supplemental" , "Exceptionally" .)