1040 or W-2
I believe the answer is:
form
'1040 or w-2' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for form that I've seen before include "A class in a school or a hare's lair" , "Group of schoolchildren < > construct" , "Printed document with spaces to write" , "Seat" , "Class; schedule" .)