Regret in equal measure (5)

I believe the answer is:

qualm

'regret' is the definition.
(thesaurus)

'in equal measure' is the wordplay.
'in' indicates a hidden word.
'QUALM' can be found hidden inside 'equal measure'.

(Other definitions for qualm that I've seen before include "Uneasiness of conscience" , "Scruple" , "Sudden feeling of unease or misgiving" , "Feeling of doubt" , "Sudden doubt, nausea" .)

I've seen this clue in the Evening Standard.

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