a group of physical and emotional symptoms that may precede a menstrual period, as fluid retention, fatigue, depression, irritability, etc.
See premenstrual syndrome in American Heritage Dictionary 4
noun Abbr. PMS
A varied group of physical and psychological symptoms, including abdominal bloating, breast tenderness, headache, fatigue, irritability, anxiety, and depression, that occur from 2 to 7 days before the onset of menstruation and cease shortly after menses begins.