The term MOM IN 'HAIRSPRAY' is referring to the character Edna Turnblad, played by John Travolta in the 2007 musical film adaptation of the Broadway musical of the same name. Edna is the mother of the protagonist Tracy Turnblad and is a larger-than-life character who loves to dance and sing. She is an iconic figure in the movie and is remembered for her big hair and larger-than-life personality.