50 had meal but not on time (4)
I believe the answer is:
late
'not on time' is the definition.
(I've seen this in another clue)
'50 had meal' is the wordplay.
'50' becomes 'l' (Roman numeral).
'had meal' becomes 'ate' (to have a meal is to eat).
'l'+'ate'='LATE'
'but' is the link.
(Other definitions for late that I've seen before include "Still to come - already gone!" , "Dead - tardy" , "Recently deceased" , "near the end" , "Yet to arrive?" .)