Czechoslovakian UK /ˈtʃɛk.əz.lə.væk.i.ən/US /ˌt͡ʃɛk.ə.sloʊˈvɑk.i.ən/adjective 1noun 1forms 1 adjective1 •Of or pertaining to the former nation of Czechoslovakia. noun1 •(historical) A person from Czechoslovakia. formsCzechoslovakians