Curtailed proposal involving place away from work (3-4)
I believe the answer is:
off-site
'away from work' is the definition.
(I've seen this before)
'curtailed proposal involving place' is the wordplay.
'curtailed' means to remove the last letter.
'proposal' becomes 'offer' (I've seen this before).
'involving' indicates putting letters inside.
'place' becomes 'sit' (sitting is a kind of placing).
'offer' with its final letter taken off is 'offe'.
'offe' going around 'sit' is 'OFF-SITE'.
(Another definition for off-site that I've seen is " (Happening) away from a work location".)