Working out meaning at increase (12)

I believe the answer is:

augmentation

'increase' is the definition.
(augmentation is a kind of increase)

'working out meaning at' is the wordplay.
'working' indicates anagramming the letters.
'out'+'meaning'+'at'='outmeaningat'
'outmeaningat' with letters rearranged gives 'AUGMENTATION'.

(Another definition for augmentation that I've seen is " increase".)

I've seen this clue in The Telegraph.

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