Perfect neatness (5-3,5)
I believe the answer is:
apple-pie order
'perfect neatness' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for apple-pie order that I've seen before include "Perfectly tidy" , "Perfect state of neatness" , "Everything precisely in its place" , "Excellent shape" , "Perfect arrangement" .)