noun

• An early human or closely related species, popularly held to reside in caves.
• (informal, figuratively, derogatory) A person with backward, primitive behavior, opinions, or interests.
• (informal, figuratively, derogatory) A brutish person, one who behaves in a rough, uncivilized way.
• (informal, figuratively, derogatory) Someone, especially a man, who has regressive, old-fashioned attitudes, particularly with regard to women; someone opposed to change or modernity.