Flimsy paper stored in folder (7)
I believe the answer is:
fragile
'flimsy' is the definition.
(thesaurus)
'paper stored in folder' is the wordplay.
'paper' becomes 'rag' (rag is a kind of paper).
'stored in' is an insertion indicator.
'folder' becomes 'file' (file folder is a kind of folder).
'rag' inserted within 'file' is 'FRAGILE'.
(Other definitions for fragile that I've seen before include "Easily broken or damaged" , "Delicate; easily broken" , "Liable to break easily" , "Not robust" , "Delicate, tenuous" .)