Item for cleaning excessively black bird cages (10)
I believe the answer is:
toothbrush
'item for cleaning' is the definition.
I can't judge whether this defines the answer.
'excessively black bird cages' is the wordplay.
'excessively' becomes 'too' (to too great a degree).
'black' becomes 'b' (as in pencil classifications).
'bird' becomes 'thrush' (thrush is a kind of bird).
'cages' indicates putting letters inside.
'b' put inside 'thrush' is 'thbrush'.
'too'+'thbrush'='TOOTHBRUSH'
Can you help me to learn more?
(Other definitions for toothbrush that I've seen before include "One found in toilet bag" , "Dental cleaner" .)