Crossword? Hard work not new (4)
I believe the answer is:
grid
'crossword?' is the definition.
(a crossword grid)
'hard work not new' is the wordplay.
'hard work' becomes 'grind' (I've seen this before).
'not' indicates named letters should be taken away.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'grind' with 'n' taken away is 'GRID'.
(Other definitions for grid that I've seen before include "Map reference system" , "Network of horizontal and vertical lines" , "Network of crossing parallel lines" , "Framework of crossing lines" , "Network of spaced lines" .)