Egyptian god with large flag (6)
I believe the answer is:
osiris
'egyptian god' is the definition.
(Osiris is an example)
'with large flag' is the wordplay.
'with' is a charade indicator (letters next to each other).
'large' becomes 'os' (abbreviation for oversize).
'flag' becomes 'iris' (type of iris flower).
'os'+'iris' is 'OSIRIS'.
(Other definitions for osiris that I've seen before include "Egyptian god, father of Horus" , "Egyptian god of the underworld" , "once highly esteemed by Egyptians" , "dead judge?" , "Husband of Isis, father of Horus - sis or I (anag)" .)