Redneck is a derogatory term mainly applied to white Americans perceived to be crass and unsophisticated, closely associated with rural whites of the southern United States.
Its meaning possibly stems from the sunburn found on farmers' necks dating back to the late 19th century.
Authors Joseph Flora and Lucinda MacKethan describe the stereotype as follows:Redneck is a derogatory term currently applied to some lower-class and working-class southerners. The term, which came into common usage in the 1930s, is derived from the redneck's beginnings as a "yeoman farmer" whose neck would burn as he or she toiled in the fields. These yeoman farmers settled along the Virginia, North Carolina, and South Carolina coasts.