Caveman

From cave + man, based on the supposition that early humans dwelt in caves.

Full definition of caveman

(plural cavemen)

An early human or closely related species, popularly held to reside in caves.The political cartoon showed the politician as a caveman, clubbing the budget depicted as a mammoth.

2006, Harley Pasternak, The 5 Factor Diet, page 15,CAVEMAN DIETThe creators of this nutrition plan believe that cavemen and cavewomen were lean and healthy because of the all-natural foods they ate.
2010, Terence A. Shimp, Advertising, Promotion, and Other Aspects of Integrated Marketing Communications, Cengage Learning, 8th Edition, page 154,And who could forget those ads that featured sophisticated cavemen who were insultedâ€”in a parody on political correctnessâ€”by â€œinsensitiveâ€ offenders who implied that some action was â€œso easy, a caveman could do it.â€
2010, Allen A. Debus, Prehistoric Monsters: The Real and Imagined Creatures of the Past That We Love to Fear, page 87,For, in essence, the caveman concept implies the abhorrentâ€”undignified human bestiality and a disquieting association with apelike ancestors. Cavemen have represented Darwinâ€²s repugnant evolutionary ideals and even suggest civilisationâ€²s tenuousness.

(informal, figuratively, pejorative) A brutish or savage person.The football squad was comprised of cavemen who were responsible for trashing many a locker room.
(informal, figuratively, pejorative) A man with old fashioned or backward opinions, particularly with regard to women.Old Sven is a bit of a caveman; he figures giving women the right to vote was a bad idea.

2008, David E. Clarke, Cinderella Meets the Caveman: Stop the Boredom in Your Marriage and Jump, page 159,You think your Caveman is always chasing you for sex. Well, he is.