Crazy chat was indeed unhinged (8)
I believe the answer is:
detached
'unhinged' is the definition.
Both the answer and definition are adjectives. Perhaps there's a link between them I don't understand?
'crazy chat was indeed' is the wordplay.
I cannot really understand how this works, but
an anagram of 'chat' is 'tach' which is within the answer.
The remaining letters 'deed' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for detached that I've seen before include "being sent on special assignment" , "free of ties" , "Separated from - maybe a house" , "Separate, disconnected" , "Type of house" .)