satem

adjective

designating or of the group of Indo-European languages, including Indo-Iranian, Slavic, Baltic, Albanian, and Armenian, in which a prehistoric change of certain original stops into sibilants sets these languages apart from those of the centum group

Etymology: < Avestan satəm, hundred < Sans sátám: see hundred): so named because the initial sound illustrates the typical development in this group of the IE palatal stop, which in the centum group is a velar stop