Czechoslovak

[chek-uh-sloh-vak, -vahk] /ˈtʃɛk əˈsloʊ væk, -vɑk/
noun
1.
a member of the branch of the Slavic peoples comprising the Czechs proper, the Moravians, and the Slovaks.
2.
a native or inhabitant of the former Czechoslovakia.
adjective
3.
of or pertaining to to the former Czechoslovakia, its people, or their language.
Also, Czecho-Slovak.
British Dictionary definitions for Czechoslovak

Czechoslovak

/ˌtʃɛkəʊˈsləʊvæk/
adjective
1.
of, relating to, or characteristic of the former Czechoslovakia, its peoples, or their languages
noun
2.
(loosely) either of the two mutually intelligible languages of the former Czechoslovakia; Czech or Slovak