Definition: Coolgirl is an internet slang term for a person who displays a strong, unapologetic attitude towards fashion and style. It's often used to describe someone with a lot of confidence or flair in their clothing choices. This can range from extreme fashion statements (like wearing a full-body purple wig) to more subtle personal styles (like rocking a boho-style ensemble). Just be careful what you say about these girls - they're definitely not all that cool!