Rapacious swaggering dandies avoiding losing head (12)

I believe the answer is:

bloodsucking

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'rapacious' is the definition.
(thesaurus)

'swaggering dandies avoiding losing head' is the wordplay.
'swaggering dandies' becomes 'bloods' (I am not sure about this - if you are sure you should believe this answer much more).
'avoiding' becomes 'ducking' (duck can mean to avoid).
'losing head' means to remove the first letter.
'ducking' with its first letter removed is 'ucking'.
'bloods'+'ucking'='BLOODSUCKING'

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(Another definition for bloodsucking that I've seen is " Like mosquitoes".)

I've seen this clue in The Independent.

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