wintergirlfriend (noun) /wntr)gər(-ə)l-frend/ 1.women who allows you to have sexual relations with her from Halloween to Patties Day. 2.women in an urban area in which the temperature falls below 40 degrees a portion of the year that is used as a non verbal companion during Pro football and College basketball. 3.women to get you through winter until the first day other women start wearing sun dresses again.