Hate mouse upsetting fellow resident (9)

I believe the answer is:

housemate

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

'resident' is the definition.
(I know that housemate is a type of resident)

'hate mouse upsetting' is the wordplay.
'upsetting' indicates anagramming the letters.
'hate'+'mouse'='hatemouse'
'hatemouse' anagrammed gives 'HOUSEMATE'.

'fellow' acts as a link.
I am not very happy about this link. It may be part of another bit of the clue.

Can you help me to learn more?

(Other definitions for housemate that I've seen before include "One sharing accommodation" , "person to live with" , "One who shares a residence" , "Co-tenant" .)

I've seen this clue in The Mirror.

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