First off, just look (3)
I believe the answer is:
air
'look' is the definition.
(I've seen this before)
'first off just' is the wordplay.
'first off' means to remove the first letter.
'just' becomes 'fair' ('fair' is associated in meaning with 'just').
'fair' with its initial letter removed is 'AIR'.
(Other definitions for air that I've seen before include "Space above and around" , "Musical composition" , "Ventilate, say grievance" , "Refrain" , "Vent; atmosphere" .)