Asterix, say (4)
I believe the answer is:
gaul
'asterix say' is the definition.
(Asterix is a Gaul in a series of comic books)
This is all the clue.
(Other definitions for gaul that I've seen before include "Ancient area of western Europe" , "Roman France" , "Caesar's name for old France" , "old country" , "Name given for ancient France from Celtic times" .)