Old queen calming undisciplined bombast (13)

I believe the answer is:

magniloquence

'bombast' is the definition.
(I've seen this before)

'old queen calming undisciplined' is the wordplay.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'undisciplined' indicates anagramming the letters.
'o'+'queen'+'calming'='oqueencalming'
'oqueencalming' with letters rearranged gives 'MAGNILOQUENCE'.

(Another definition for magniloquence that I've seen is " Bombast".)

I've seen this clue in The Times.

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