The way something is arranged or set out (6)
I believe the answer is:
format
'the way something is arranged or set out' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for format that I've seen before include "Style or arrangement of procedure" , "Arrangement or lay-out, say of book" , "Structure, layout" , "Style or arrangement of a TV programme" , "Arrangement (data)" .)