The Poles (Polish: Polacy, pronounced [pɔˈlat͡sɨ]; singular masculine: Polak, singular feminine: Polka) are a nation and West Slavic ethnic group native to Poland. The population of Poles in Poland is estimated at 37,394,000 out of an overall population of 38,538,000 (based on the 2011 census). The preamble to the Constitution of the Republic of Poland defines the Polish nation as comprising all the citizens of Poland; ethnicity is a private matter of each citizen. Poland's population inhabits several historic regions such as Greater Poland, Lesser Poland, Mazovia, Silesia, Pomerania, Kuyavia, Warmia (Ermland), Masuria, and Podlachia.