The term “Crosby” primarily refers to a proper noun, often used as a surname. It is associated with various notable individuals, such as Bing Crosby, an American singer and actor famous for his smooth baritone voice and significant contributions to music and film in the 20th century. Additionally, “Crosby” can also refer to places, such as towns or geographical locations, particularly in the United Kingdom and the United States. In these contexts, it does not have a specific definition beyond being a name or proper noun. If you are referring to a specific context or meaning of “Crosby,” please provide more details.