Balkan Peninsula bal·kan·pe·ninsula uncommon noun 1. a large peninsula in southeastern Europe containing the Balkan Mountain Range SynonymsBalkan PeninsulaBalkans Related words Broader terms peninsula Parts Europe Part of Balkan WarsBalkan countryAlbaniaCroatiaMacedonThraceMacedoniaTurkey WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.