Concept everyone associated at first with papers (4)
I believe the answer is:
idea
'concept' is the definition.
(I've seen this before)
'everyone associated at first with papers' is the wordplay.
'at first' indicates taking the first letters.
'with' says to put letters next to each other.
'papers' becomes 'id' (identification papers).
The initial letters of 'everyone associated' is 'ea'.
'ea' after 'id' is 'IDEA'.
(Other definitions for idea that I've seen before include "Inkling" , "Notion, image" , "Mental impression" , "A suspicion of" , "Product of the mind" .)