Tear right back (4)
I believe the answer is:
rend
'tear' is the definition.
(rending is a kind of tearing)
'right back' is the wordplay.
'right' becomes 'r' (common abbreviation).
'back' becomes 'end' (I've seen this in other clues).
'r'+'end'='REND'
(Other definitions for rend that I've seen before include "Tear to pieces" , "Tear apart, wrench" , "Nerd (anag.)" , "Rip" , "Tear apart roughly" .)