Rigid impression surfacing about new head of Royal Mail (9)

I believe the answer is:

tramlined

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'rigid' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives occasionally mean the same thing.

'impression surfacing about new head of royal mail' is the wordplay.
'impression' becomes 'dent' (dent is a kind of impression).
'surfacing' says the letters should be written in reverse (as opposed to capsizing).
'about' means one lot of letters goes inside another.
'new' is an anagram indicator.
'head of' indicates taking the first letters.
The first letter of 'royal' is 'r'.
'dent' backwards is 'tned'.
'r'+'mail'='rmail'
'rmail' anagrammed gives 'ramli'.
'tned' enclosing 'ramli' is 'TRAMLINED'.

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I've seen this clue in The Times.

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