South African boy leaves for lunch? (5)
I believe the answer is:
salad
'leaves for lunch?' is the definition.
(I've seen this in another clue)
'south african boy' is the wordplay.
'south african' becomes 'SA' (abbreviation).
'boy' becomes 'lad' (informal term for boy).
'sa'+'lad'='SALAD'
(Other definitions for salad that I've seen before include "Cold vegetable dish" , "A cold meal with lots of lettuce" , "See 22" , "One that may be dressed for dinner" , "Mixed food" .)