momma bear noun 2adjective 1forms 1 noun2 •(informal) A female bear currently rearing one or more cubs. •(slang) A woman, especially a mother, who is extremely protective of a child or children.To my sister, Kristen, who wears the badge of motherhood with pride and inspires people to love without reservation, without judgment, without fear. She is a mama bear and a wonder to watch in action! — 2009 adjective1 •Characteristic of protective maternal behavior. formsmomma bears