Proto-Indo-European

[ proh-toh-in-doh-yoo r-uh-pee-uh n ]
/ ˈproʊ toʊˌɪn doʊˌyʊər əˈpi ən /

noun

the unattested prehistoric parent language of the Indo-European languages; Indo-European.

adjective

of or relating to Proto-Indo-European.

British Dictionary definitions for proto-indo-european

Proto-Indo-European

noun

the prehistoric unrecorded language that was the ancestor of all Indo-European languages