Employing us in middle-age (5)

I believe the answer is:

using

'employing' is the definition.
(to employ is to use)

'us in middle-age' is the wordplay.
'middle' means to look at the middle letters.
The central letter of 'age' is 'g'.
'us'+'in'+'g'='USING'

(Other definitions for using that I've seen before include "addiction" , "Putting into service" , "Exercising" , "Putting to a particular purpose" , "Employing" .)

I've seen this clue in the Evening Standard.

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