Wait up till late, finally getting something to eat (6)
I believe the answer is:
edible
'something to eat' is the definition.
(edible is a kind of food)
'wait up till late finally' is the wordplay.
'wait' becomes 'bide' (I've seen this before).
'up' is a reversal indicator (in down clue: letters go upwards).
'finally' indicates one should take the final letters.
The last letters of 'till late' are 'le'.
'bide' reversed gives 'edib'.
'edib'+'le'='EDIBLE'
'getting' is the link.
(Other definitions for edible that I've seen before include "Able to be eaten" , "Belied (anag)" , "Safe to eat" , "Palatable" , "Fit to be used as food" .)