Be unbalanced as cow almost leaves horse rattled (4,1,5,5)
I believe the answer is:
have a screw loose
'be unbalanced' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'as cow almost leaves horse rattled' is the wordplay.
'almost' means to remove the last letter (most of the word but not all of it).
'rattled' is an anagram indicator.
'leaves' with its final letter removed is 'leave'.
'as'+'cow'+'leave'+'horse'='ascowleavehorse'
'ascowleavehorse' anagrammed gives 'HAVE A SCREW LOOSE'.
Can you help me to learn more?
(Other definitions for have a screw loose that I've seen before include "A ship with a propeller certainly" , "Brand new item from carpenter shouldn't" , "shouldn't be touched" , "Be crazy" , "defective?" .)