Come into Rhine, swimming it (7)
I believe the answer is:
'come into' is the definition.
'rhine swimming it' is the wordplay.
'swimming' indicates anagramming the letters.
'rhine' with letters rearranged gives 'inher'.
(Other definitions for inherit that I've seen before include "Come into (money)" , "Acquire from ancestors" , "Obtain as legacy" , "Receive as a legacy" , "Get what was left?" .)