The mum dashing around got off to a brisk start (4,6,3)

I believe the answer is:

made things hum

'got off to a brisk start' is the definition.

'the mum dashing around' is the wordplay.
'around' is an anagram indicator.
'the'+'mum'+'dashing'='themumdashing'
'themumdashing' is an anagram of 'MADE THINGS HUM'.

I've seen this clue in The Guardian.

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