I. ˌin-dō-ˌyu̇r-ə-ˈpē-ən adjective
Date: 1813
: of, relating to, or constituting the Indo-European languages
II. noun
Date: 1832
1.
a. : a member of the people speaking an unrecorded prehistoric language from which the Indo-European languages are descended
b. : this language
2. : Indo-European languages