European follows awfully glib nonsense (5)
I believe the answer is:
bilge
'nonsense' is the definition.
(I've seen this before)
'european follows awfully glib' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'follows' says to put letters next to each other.
'awfully' indicates anagramming the letters.
'glib' with letters rearranged gives 'bilg'.
'e' put after 'bilg' is 'BILGE'.
(Other definitions for bilge that I've seen before include "Piffle - part of hull" , "Rubbish like waste water in ship" , "Lowest internal portion of a ship's hull" , "Very long film, book etc" , "Dirty water collecting on a vessel" .)