Inventor; the boxer's saviour, perhaps (4)

I believe the answer is:

bell

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'inventor' is the definition.
(I've seen this before)

I don't understand the rest of the clue.

(Other definitions for bell that I've seen before include "Buzz" , "Instrument making ringing sound" , "It rings when struck" , "inventive fellow" , "Stag's cry; ringer" .)

I've seen this clue in the Evening Standard.

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