Foolish, stirring up endless dispute (6)
I believe the answer is:
stupid
'foolish' is the definition.
(similar in meaning)
'stirring up endless dispute' is the wordplay.
'stirring up' indicates anagramming the letters.
'endless' means to remove the last letter.
'dispute' with its final letter taken off is 'disput'.
'disput' with letters rearranged gives 'STUPID'.
(Other definitions for stupid that I've seen before include "Dull" , "Ignorant" , "Gormless" , "Senseless" , "Barmy" .)