Melodious singer, beagle? (9)
I believe the answer is:
blackbird
'beagle?' is the definition.
The answer and definition can be both animals as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'melodious singer' is the wordplay.
'melodious' becomes 'black' (I can't justify this - if you can you should give a lot more credence to this answer).
'singer' becomes 'bird' (synonyms).
'black'+'bird'='BLACKBIRD'
Can you help me to learn more?
(Other definitions for blackbird that I've seen before include "garden pecker pecker" , "Relative of thrush" , "slave on ship" , "It has a yellow bill" , "One of 24 in pie" .)