indoeiropeisks

Etymology
From (indo- is a nationality prefix corresponding to India), following the pattern of other similar formations in other European languages (cf. 🇨🇬, 🇨🇬, all tracing back to Sir Thomas Young's original  1813 coinage ).

Adjective

 * 1) Indo-European relating to the presumed Indo-European people, to their presumed language, Proto-Indo-European, or their culture; relating to the present-day languages, peoples and cultures derived from the ancient Proto-Indo-Europeans

Usage notes
English “Indo-European” as an attributive adjective usually corresponds in Latvian to, the genitive plural form of. The adjective is commonly used as a predicate (“this is Indo-European”), or in its adverbial form.