Awful new boring group (4)
I believe the answer is:
band
'group' is the definition.
(band is a kind of group)
'awful new boring' is the wordplay.
'awful' becomes 'bad' (similar in meaning).
'new' becomes 'n'.
'boring' means one lot of letters goes inside another (some letters must 'bore' a hole into other letters).
'bad' going around 'n' is 'BAND'.
(Other definitions for band that I've seen before include "Loop; rock group" , "Players" , "Pop group, perhaps" , "Orchestra" , "Strip, belt; playing group" .)