- the Indo-European family of languages: its principal branches are Albanian, Anatolian, Armenian, Baltic, Celtic, Germanic, Greek, Indic, Iranian (often grouped with Indic as the Indo-Iranian subfamily), Italic, Slavic, and Tocharian
- the hypothetical language, reconstructed by modern linguists, from which these languages are thought to have descended: in this sense, Proto-Indo-European is now the preferred term
- a member of a people that speaks an Indo-European language
- a hypothetical speaker of Proto-Indo-European
- a. A family of languages consisting of most of the languages of Europe as well as those of Iran, the Indian subcontinent, and other parts of Asia.b. Proto-Indo-European.
- A member of any of the peoples speaking an Indo-European language.
(comparative more Indo-European, superlative most Indo-European)
- Of or relating to the languages originally spoken in Europe and Western Asia.
- Of or relating to the hypothetical parent language of the Indo-European language family. Also called Proto-Indo-European and abbreviated PIE.
- Of or relating to the hypothetical group of peoples that spread Indo-European languages.