It's any arrangement that makes good sense (6)
I believe the answer is:
sanity
'good sense' is the definition.
(sanity can mean thinking sensibly)
'it's any arrangement' is the wordplay.
'arrangement' indicates anagramming the letters.
'its'+'any'='itsany'
'itsany' with letters rearranged gives 'SANITY'.
'that makes' is the link.
(Other definitions for sanity that I've seen before include "Sound sense" , "Rational state" , "Reason, condition of being compos mentis" , "Soundness of mind" , "Balance of mind" .)