premenstrual UK /ˌpɹiːˈmɛnstɹʊəl/US /pɹiˈmɛnztɹ(əw)əl/ adjective2 •Occurring in the time period during the menstrual cycle leading up to the beginning of menstruation. •Relating to the time period in a girl's life prior to her first experience of menstruation; prepubescent. formsmore premenstrual · most premenstrual