Circulation of family confused master (11)
I believe the answer is:
bloodstream
'circulation' is the definition.
(thesaurus)
'family confused master' is the wordplay.
'family' becomes 'blood' (I've seen this in other clues).
'confused' indicates an anagram.
'master' with letters rearranged gives 'stream'.
'blood'+'stream'='BLOODSTREAM'
'of' acts as a link.
(Other definitions for bloodstream that I've seen before include "current in vessels" , "Vital channel" , "It circulates in vessels" , "something essential to human life" , "vital passage" .)