structural:expansion, stylistic:style_transfer, stylistic:tone
Etymology

The word sauna is an ancient Finnish word referring to both the traditional Finnish bath and to the bathhouse itself. In Finnic languages other than Finnish and Estonian, sauna and cognates do not necessarily mean a building or space built for bathing. It can also mean a small cabin or cottage, such as a cabin for a fisherman. The word is the best known Finnicism in many languages.