belonging to or consisting of those branches of the Indo-European family in which alveolar or palatal fricatives, as the sounds (s) or (sh), developed in ancient times from Proto-Indo-European palatal stops: the satem branches are Indo-Iranian, Armenian, Slavic, Baltic, and Albanian.
Origin of satem
1900–05; < Avestan satəm hundred (cognate with Latin centum; see centum2), exemplifying in s- the outcome of Indo-European palatal stops characteristic of the group
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
denoting or belonging to the group of Indo-European languages in which original velar stops became palatalized (k > s or / ʃ /). These languages belong to the Indic, Iranian, Armenian, Slavonic, Baltic, and Albanian branches and are traditionally regarded as the E groupCompare centum
Word Origin for satem
from Avestan sat ə m hundred; chosen to exemplify the variation of initial s with initial k (as in centum) in Indo-European languages
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012