Honky-tonk refers to two things:
A type of ragtime music characterized by its upbeat rhythm, often associated with the Southern parts of the United States, particularly with bars or dance halls that feature this type of music.
A cheap, noisy bar or dance hall, especially in the Southern U.S., typically featuring this music. Besides drinking, dancing, and socializing, such venues could also include entertainment like pool tables, mechanical bull riding, or live music performances.