Amazon v Inland Revenue , in the past? (6)
I believe the answer is:
virago
'amazon' is the definition.
(synonyms)
'v inland revenue in the past?' is the wordplay.
'inland revenue' becomes 'ir' (abbreviation for Inland Revenue).
'in the past?' becomes 'ago' (three years ago means three years in the past).
'v'+'ir'+'ago'='VIRAGO'
(Other definitions for virago that I've seen before include "Dominating woman" , "A tough abusive woman" , "Manlike woman?" , "Formidable female" , "Scold" .)