An Etymological Dictionary of Astronomy and Astrophysics

Prefix denoting one-hundredth of, in metric units; e.g. centimeter, 0.01 of meter.

Etymology (EN): Fr., from L. centi,- “hundred,” from centum “hundred,” Gk. hekaton, Av. satem-, Mod.Pers. sad, Skt. satam-, P.Gmc. *hunda- “hundred,” Goth. hund, O.H.G. hunt, O.Ir. cet, Bret. kant,
PIE *kmtom “hundred.”

Etymology (PE): Sânti-, from Fr., → above paragraph.