Is a better paint remover than? (9)

I believe the answer is:

outstrips

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'is' is the definition.
Although both the answer and definition are verbs in their -s form, I can't understand how one could define the other.

I don't understand how the rest of the clue works.

Can you help me to learn more?

(Other definitions for outstrips that I've seen before include "Overtakes; exceeds" , "trumps" .)

I've seen this clue in the Evening Standard.

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