First two characters to leave Belgian town (5)
I believe the answer is:
elgin
'town' is the definition.
(I know that Elgin is a town of the United States)
'first two characters to leave belgian' is the wordplay.
'first two characters' becomes 'ab' (A and B are the first letters of the alphabet).
'to leave' is a deletion indicator.
'belgian' with 'ab' taken away is 'ELGIN'.
(Other definitions for elgin that I've seen before include "Marble-gathering earl" , "Parthenon marbles remover" , "Moray town, Earldom" , "Sculpture collector" , "Scots town; - marbles" .)