Tear somewhat horrendously? (4)
I believe the answer is:
rend
'tear' is the definition.
(I know that rend is a more specific form of the action tear)
'somewhat horrendously' is the wordplay.
'somewhat' indicates a hidden word.
'REND' can be found hidden inside 'horrendously'.
(Other definitions for rend that I've seen before include "Tear violently" , "Tear apart, wrench" , "Tear, sunder" , "Cleave" , "Tear savagely" .)