Girl’s gruff sound fast brought about this writer’s grumpiness (14)

I believe the answer is:

disgruntlement

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'grumpiness' is the definition.
Although both the answer and definition are singular nouns, I can't understand how they can define each other.

'girl's gruff sound fast brought about this writer's' is the wordplay.
'girl's' becomes 'Dis' (Di is short for Diana).
'gruff sound' becomes 'grunt' (I have seen 'Inarticulate sound ' mean 'grunt' so perhaps 'sound' could also mean 'grunt'. I am not sure about the 'gruff' bit.).
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
'brought about' is an insertion indicator.
'this writer' becomes 'me' (the person who is writing these clues).
'lent' placed around 'me' is 'lement'.
'dis'+'grunt'+'lement'='DISGRUNTLEMENT'

Can you help me to learn more?

(Another definition for disgruntlement that I've seen is " Dissatisfied anger".)

I've seen this clue in The Times.

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