Dog's dinner - very large tea first (5)
I believe the answer is:
chaos
'dog's dinner' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'very large tea first' is the wordplay.
'very large' becomes 'os' (abbreviation for oversize).
'tea' becomes 'cha' (cha is a type of tea).
'first' means one lot of letters go next to another.
'os' after 'cha' is 'CHAOS'.
Can you help me to learn more?
(Other definitions for chaos that I've seen before include "Pandemonium" , "Total disorder and confusion" , "Bedlam" , "mess" , "Totally disordered state" .)