Angry it's on the hat rack (3,4,4)
I believe the answer is:
off ones head
'hat rack' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'angry it's on' is the wordplay.
I cannot really understand how this works, but
'it's' could be 'es' ('e' can mean 'electronic' which is similar to 'IT') and 'es' is found in the answer.
'on' is found in the answer.
This explanation may well be incorrect...
'the' is the link.
Can you help me to learn more?
(Other definitions for off ones head that I've seen before include "deranged" , "wasted" , "Cap in hand is so" .)