Wise men entertaining prince with European bird (6)
I believe the answer is:
magpie
'bird' is the definition.
(magpie is a kind of bird)
'wise men entertaining prince with european' is the wordplay.
'wise men' becomes 'magi' (the three wise men from the nativity).
'entertaining' indicates putting letters inside.
'prince' becomes 'p'.
'with' says to put letters next to each other.
'european' becomes 'e' (abbreviation e.g. EU).
'magi' placed around 'p' is 'magpi'.
'magpi'+'e'='MAGPIE'
(Other definitions for magpie that I've seen before include "Pied bird" , "Black and white bird - a thief" , "Black-and-white crow" , "Black and white bird, may be thieving" , "winger" .)