The morning everyone returns an animal (5)
I believe the answer is:
llama
'an animal' is the definition.
(I've seen this before)
'the morning everyone returns' is the wordplay.
'the morning' becomes 'am'.
'everyone' becomes 'all' (all people).
'returns' says the letters should be written backwards.
'am'+'all'='amall'
'amall' backwards is 'LLAMA'.
(Other definitions for llama that I've seen before include "South American beast of burden" , "Peruvian camel" , "one to chew the cud" , "Andean beast of burden" , "One bearing burden" .)