a house where people pay to have sex with prostitutes Word Origin mid 16th cent. (originally brothel-house): from late Middle English brothel ‘worthless man, prostitute’, related to Old English brēothan ‘degenerate, deteriorate’.Extra examples He used to visit a brothel in Paris. He used to visit a brothel on the outskirts of town. His aunt ran a brothel. She ran a brothel in Soho.