[proh-toh-in-doh-yoo r-uh-pee-uh n]
- the unattested prehistoric parent language of the Indo-European languages; Indo-European.
- of or relating to Proto-Indo-European.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- the prehistoric unrecorded language that was the ancestor of all Indo-European languages