Have leading role in school to execute (6)
I believe the answer is:
behead
'to execute' is the definition.
(I know that behead is a more specific form of execute)
'have leading role in school' is the wordplay.
I cannot quite see how this works, but
'leading' could be 'head' (I've seen this in other clues) and 'head' is present in the answer.
The remaining letters 'be' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for behead that I've seen before include "Top" , "Remove the crown" , "Guillotine" , "wield the axe" , "Execute with axe as in olden days" .)