Decoration woven by a bird (5)
I believe the answer is:
braid
'decoration' is the definition.
(braid is a kind of decoration)
'woven by a bird' is the wordplay.
'woven' is an anagram indicator.
'by' means one lot of letters go next to another.
'a' next to 'bird' is 'abird'.
'abird' anagrammed gives 'BRAID'.
(Other definitions for braid that I've seen before include "Woven ornamental trimming, often gold" , "Gilded ribbon" , "Interlaced link of hair strands" , "woven fabric" , "decoration" .)