They once set the fashion for hurried activities (7)

I believe the answer is:

bustles

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'they once set' is the definition.
The definition suggests an adverb but the answer is not.

'fashion for hurried activities' is the wordplay.
'fashion' becomes 'bustle' (I have seen 'Victorian fashion' mean 'bustle' so perhaps 'fashion' could also mean 'bustle').
'for' means one lot of letters go next to another.
'hurried activities' becomes 's' (I can't justify this - if you can you should give a lot more credence to this answer).
'bustle'+'s'='BUSTLES'

'the' is the link.

Can you help me to learn more?

I've seen this clue in The Irish Independent.

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