Brown gear worn for singer (7)
I believe the answer is:
tanager
'for singer' is the definition.
(tanager is a kind of birdanimal)
'brown gear worn' is the wordplay.
'brown' becomes 'tan' (tan is a kind of brown).
'worn' indicates an anagram (worn can mean damaged).
'gear' with letters rearranged gives 'ager'.
'tan'+'ager'='TANAGER'
(Other definitions for tanager that I've seen before include "A bird" , "Songbird of the bunting family" , "South American singer" , "American songbird" .)