Mum rants terribly, producing oft-repeated phrases (7)

I believe the answer is:

mantras

'oft-repeated phrases' is the definition.
(a mantra is a repeated phrase or incantation)

'mum rants terribly' is the wordplay.
'mum' becomes 'ma' (ma can mean mother).
'terribly' indicates an anagram.
'rants' anagrammed gives 'ntras'.
'ma'+'ntras'='MANTRAS'

'producing' is the link.

(Another definition for mantras that I've seen is " Aids to meditation".)

I've seen this clue in The Times.

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