Harshly criticise long dash (7)

I believe the answer is:

panache

'dash' is the definition.
('panache' can be a synonym of 'dash')

'harshly criticise long' is the wordplay.
'harshly criticise' becomes 'pan'.
'long' becomes 'ache' ('ache' can be a synonym of 'long').
'pan'+'ache'='PANACHE'

(Other definitions for panache that I've seen before include "Dashing style" , "'Dash, flair (7)'" , "Swagger; theatricality" , "A dashing manner" , "flourish" .)

I've seen this clue in The Guardian.

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