Expression of contempt from stupid person (5)
I believe the answer is:
booby
'stupid person' is the definition.
(I've seen this before)
'expression of contempt from' is the wordplay.
I cannot quite understand how this works, but
'expression' could be 'boo' (I have seen 'Expression of disapproval' mean 'boo' so perhaps 'expression' could also mean 'boo') and 'boo' is found in the answer.
'from' could be 'by' (by can mean from a particular person) and 'by' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for booby that I've seen before include "Pink-footed seabird" , "marine bird" , "Dunce" , "Gannet" , "Sort of trap" .)