Canadian songster scoffing a trifle (6)
I believe the answer is:
bauble
'trifle' is the definition.
(I've seen this in another clue)
'canadian songster scoffing a' is the wordplay.
'canadian songster' becomes 'Buble' (Canadian singer Michael Buble).
'scoffing' means one lot of letters goes inside another.
'buble' going around 'a' is 'BAUBLE'.
(Other definitions for bauble that I've seen before include "Small cheap trinket" , "'Bead, trinket (6)'" , "worthless D [DECORATION]" , "Showy trinket" , "Gaudy toy" .)