Naughty child on edge with limitless adult approval (10)

I believe the answer is:

imprimatur

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'approval' is the definition.
(imprimatur is a kind of approval)

'naughty child on edge with limitless adult' is the wordplay.
'naughty child' becomes 'imp' (informal term for a misbehaving child).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'edge with' becomes 'rim' (rim is a kind of edge. I am not sure about the 'with' bit.).
'limitless' indicates the central letters.
'adult' becomes 'mature' (similar in meaning).
The central letters of 'mature' are 'atur'.
'imp'+'rim'+'atur'='IMPRIMATUR'

Can you help me to learn more?

(Other definitions for imprimatur that I've seen before include "church licence" , "Church approval" .)

I've seen this clue in The Times.

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