Pirate taking juice regularly may tuck into brew (9)
I believe the answer is:
buccaneer
'pirate' is the definition.
(synonyms)
'juice regularly may tuck into brew' is the wordplay.
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
'may' becomes 'can' (synonyms).
'tuck into' indicates putting letters inside.
'brew' becomes 'beer' (beer is a kind of brew).
The alternating letters of 'juice' are 'uc'.
'uc'+'can'='uccan'
'uccan' put within 'beer' is 'BUCCANEER'.
'taking' is the link.
(Other definitions for buccaneer that I've seen before include "Sea wolf" , "Sea robber" , "'Sea Rover'" , "Piratical adventurer" , "Unscrupulous opportunist" .)