Engaged one tank in action (5,2)

I believe the answer is:

taken on

'engaged' is the definition.
(take on can mean to engage or employ)

'one tank in action' is the wordplay.
'in action' is an anagram indicator (I've seen this in other clues).
'one'+'tank'='onetank'
'onetank' anagrammed gives 'TAKEN ON'.

(Another definition for taken on that I've seen is " Hired".)

I've seen this clue in The Guardian.

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