Aristocrat and European prince I omitted? It should be easy to sort out (2-7)
I believe the answer is:
no-brainer
'it should be easy to sort out' is the definition.
'aristocrat and european prince' is the wordplay.
'aristocrat' becomes 'nob' (I've seen this before).
'and' says to put letters next to each other.
'european prince' becomes 'rainer' (prince of Monaco).
'nob'+'rainer'='NO-BRAINER'
'i omitted?' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
(Other definitions for no-brainer that I've seen before include "That which must be done, obviously" , "Something requiring little thought" , "Trivial problem" , "Something requiring no mental thought" , "Something involving little or no mental effort" .)