European wearing no pants (9)
I believe the answer is:
norwegian
'european' is the definition.
(I know that Norwegian is a type of european)
'wearing no pants' is the wordplay.
'pants' indicates anagramming the letters (UK informal term for 'nonsense' or 'rubbish').
'wearing'+'no'='wearingno'
'wearingno' with letters rearranged gives 'NORWEGIAN'.
(Other definitions for norwegian that I've seen before include "Native to, eg, Oslo" , "Northerner" , "From Oslo, perhaps" , "1 in 21 [OSLO] possibly" , "like King Harald I" .)