Primarily, rip on purpose? (4)

I believe the answer is:

rend

I'm a little stuck... Click here to teach me more about this clue!

'primarily rip on purpose?' is the definition.
I can't tell whether this defines the answer.

'primarily rip on purpose?' is the wordplay.
'primarily' suggests taking the first letters.
'on' is a charade indicator (letters next to each other).
'purpose?' becomes 'end' (both can mean a goal).
The first letter of 'rip' is 'r'.
'r'+'end'='REND'

Can you help me to learn more?

(Other definitions for rend that I've seen before include "Tear, sunder" , "split" , "Tear apart roughly" , "Cleave" , "Tear violently" .)

I've seen this clue in The Times.

Want a hint initially instead of a full solution? Install my app