Out-of-date teacher departed (6,2)

I believe the answer is:

passed on

'departed' is the definition.
(thesaurus)

'out-of-date teacher' is the wordplay.
'out-of-date' becomes 'passe' ('passe' can be a synonym of 'out-of-date').
'teacher' becomes 'don' (don is a kind of teacher).
'passe'+'don'='PASSED ON'

(Another definition for passed on that I've seen is " Handed over - died".)

I've seen this clue in The Telegraph.

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