Pennant, decoration (8)
I believe the answer is:
streamer
I believe this clue is a double definition.
'pennant' is the first definition.
(I know that pennant can be written as streamer)
'decoration' is the second definition.
(streamer is a kind of decoration)
(Other definitions for streamer that I've seen before include "Long decorative strip of material" , "Paper ribbon - thin flag" , "Long flag or decoration" , "Long flag -- bad cold" , "Pennant" .)