A complaint of teachers (4)

I believe the answer is:

ache

'a complaint' is the definition.

'of teachers' is the wordplay.
'of' indicates a hidden word.
'ACHE' is hidden within 'teachers'.

(Other definitions for ache that I've seen before include "Cause pain" , "A dull lingering pain" , "Take an aspirin for it" , "yearning" , "Long ? pain" .)

I've seen this clue in The Independent.

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