Contemptuous head of school with cereal, almost stuffed (8)
I believe the answer is:
scornful
'contemptuous' is the definition.
(I know that contemptuous can be written as scornful)
'head of school with cereal almost stuffed' is the wordplay.
'head of' suggests taking the first letters.
'with cereal' becomes 'corn' (corn is a kind of cereal. I am not sure about the 'with' bit.).
'almost' means to remove the last letter (most of the word but not all of it).
'stuffed' becomes 'full' (similar in meaning).
The initial letter of 'school' is 's'.
'full' with its last letter taken off is 'ful'.
's'+'corn'+'ful'='SCORNFUL'
Can you help me to learn more?
(Other definitions for scornful that I've seen before include "Contemptuous or derisory" , "Disdainful, contemptuous" , "Dismissive, contemptuous" , "Showing contempt for" , "sneering?" .)