Cutter's confused state, head spinning (4)
I believe the answer is:
adze
This might be a double definition.
'cutter's' is the first definition.
(adze is a kind of cutter)
'confused state head spinning' is the second definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
(Other definitions for adze that I've seen before include "Something with sharp edge" , "Carpenter's tool sound mathematically capable" , "Wood cutting tool" , "tool for carpenter" , "Woodworker's tool" .)