Fierce-looking dog immobilises ageing diva (8)

I believe the answer is:

pinscher

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

'fierce-looking dog' is the definition.
I can't tell whether this defines the answer.

'immobilises ageing diva' is the wordplay.
'immobilises' becomes 'pins' (I've seen this in another clue).
'ageing diva' becomes 'cher' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pins'+'cher'='PINSCHER'

Can you help me to learn more?

(Another definition for pinscher that I've seen is " dog".)

I've seen this clue in The Independent.

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