Opponents raved about small sign (11)

I believe the answer is:

adversaries

'opponents' is the definition.
('adversary' can be a synonym of 'opponent')

'raved about small sign' is the wordplay.
'about' is an anagram indicator.
'small' becomes 's' (abbreviation - e.g. clothes size).
'sign' becomes 'Aries' (star sign).
'raved' is an anagram of 'adver'.
'adver'+'s'+'aries'='ADVERSARIES'

(Another definition for adversaries that I've seen is " Enemies".)

I've seen this clue in The Daily Express.

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