Order is inane and stupid (7)
I believe the answer is:
asinine
'stupid' is the definition.
(thesaurus)
'order is inane' is the wordplay.
'order' indicates an anagram.
'is'+'inane'='isinane'
'isinane' with letters rearranged gives 'ASININE'.
'and' is the link.
(Other definitions for asinine that I've seen before include "Senseless" , "Daft" , "'Mindless, vacuous (7)'" , "Foolish like donkey" , "Is Annie? (Anag)" .)