Come into swirling Rhine ahead of it (7)
I believe the answer is:
inherit
'come into' is the definition.
('inherit' can be a synonym of 'come into')
'swirling rhine ahead of it' is the wordplay.
'swirling' indicates an anagram.
'ahead of' means one lot of letters go next to another (I've seen this in other clues).
'rhine' anagrammed gives 'inher'.
'inher'+'it'='INHERIT'
(Other definitions for inherit that I've seen before include "Benefit from willing" , "Receive as heir" , "Receive as bequest from will" , "Receive as a legacy" , "Gain by succession" .)