A comfortable place or dwelling where one feels quite at home. At first put as a home from home, this expression dates from the second half of the 1800s. In the 1920s it took its present form. The OED cites a lyric from Henry Kirk’s The Transport Workers Songbook of ca. 1926: “It’s like a home away from home.” Since then the expression has become standard usage in advertisements for hotels and other lodgings, vacation spots, and the like.