sesterce
Concise Oxford English Dictionary © 2008 Oxford University Press:
sesterce /ˈsɛstəːs/ (also sestertius /sɛˈstəːʃəs/)
▶noun (pl. sesterces /-siːz/ or sestertii /-ˈstəːʃɪiː/) an ancient Roman coin and monetary unit equal to one quarter of a denarius.
– origin from L. sestertius (nummus) ‘(coin) that is two and a half (asses)’.
'sesterce' also found in these Oxford entries:

