chill girl noun2 •(slang) A girlfriend considered by her boyfriend to be self-sufficient, "low-maintenance" and "chilled out".[Chill girls naturally] have tons of dude friends, they're not invested in the person they're casually sleeping with, and they like sports and beer. — 2014 •(Internet, disapproving) A woman who thinks feminist identity politics are unimportant or unnecessary.We can talk about sex in front of her, don’t have to get the door for her. You know, she’s a chill girl. She’s a bro. — 2012 formschill girls