Goodbye! I am returning the Japanese matting (6)
I believe the answer is:
tatami
'the japanese matting' is the definition.
The definition suggests a singular noun which matches the answer.
'goodbye i am returning' is the wordplay.
'goodbye' becomes 'tata' (I've seen this before).
'i am' becomes 'i'm'.
'returning' says the letters should be written backwards.
'im' back-to-front is 'mi'.
'tata'+'mi'='TATAMI'
Can you help me to learn more?
(Other definitions for tatami that I've seen before include "Japanese straw mat; a mat, it (anag.)" , "Jap. floor mat" , "Japanese rush and straw matting" , "Floor-covering" , "Jap. room matting" .)