Aristocrat, one rejected by prince, far from a poser (2-7)
I believe the answer is:
no-brainer
'prince far from a poser' is the definition.
I don't know anything about this answer so I can't judge whether this works.
'aristocrat one rejected' is the wordplay.
'aristocrat' becomes 'nob' (nob can mean an aristocrat).
'one rejected' becomes 'rainer' (I can't justify this - if you can you should believe this answer much more).
'nob'+'rainer'='NO-BRAINER'
'by' is the link.
Can you help me to learn more?
(Other definitions for no-brainer that I've seen before include "Obvious choice" , "It's totally clear" , "Something requiring no mental thought" , "Something needing little mental effort" , "Something requiring little thought" .)