Back rents collected (5)

I believe the answer is:

stern

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

'back' is the definition.
(stern is a kind of back)

'rents collected' is the wordplay.
'rents' can be anagrammed to 'STERN'.
But, I am not sure how this is indicated.

Can you help me to learn more?

(Other definitions for stern that I've seen before include "Severe; grimly serious" , "Unyielding - rump" , "Severe, demanding" , "Severe -- back of boat" , "Poop" .)

I've seen this clue in the Evening Standard.

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