Those lands owned or cultivated by the Hobbits, or at least familiar to them. The Hobbit-lands certainly contained the Shire and Buckland, and perhaps stretched beyond their borders. When Bilbo and the Dwarves passed out of the Hobbit-lands, they came to an unspecified place where the people used strange speech, and sang unfamiliar songs. This may be an oblique reference to the Bree-land, and if so it places Bree outside the Hobbit-lands as such, despite the fact that Hobbits lived among the Men of Bree.