From Longman Dictionary of Contemporary EnglishLithuaniaLith‧u‧a‧ni‧a /ˌlɪθjuˈeɪniə $ ˌlɪθu-/ a country in northeast Europe on the Baltic Sea, between Latvia and Poland, which used to be part of the former Soviet Union. Lithuania joined the EU in 2004. Population: 3,515,858 (2014). Capital: Vilnius. —Lithuanian noun, adjective