belonging to or consisting of those branches of the Indo-European family of languages that show distinctive preservation of the Proto-Indo-European labiovelars and that show a historical development of velar articulations, as the sounds (k) or /x/Show Spelled Pronunciation[kh]Show IPA, from Proto-Indo-European palatal phonemes. The centum branches are Germanic, Celtic, Italic, Hellenic, Anatolian, and Tocharian.
cen·tum (kěn'təm) adj. Designating those Indo-European languages, including the Italic, Hellenic, Celtic and Germanic subfamilies, that merged the palatal velar stops with the plain velars k, g, gh and maintained a distinction between them and the labiovelars kw, gw, gwh.
[Latin, hundred (a word whose initial sound in classical Latin illustrates the preservation of the Indo-European palatal velar as a velar k); see dek in Indo-European roots.]