Menstrual cramps: Cramping in the lower abdomen, usually in the first or second day of the menstrual cycle, that is caused by contractions of the uterus as it expels its unneeded contents and by the passage of clotted blood through the cervix. Ibuprofen or other pain relievers can reduce the severity of menstrual cramps, and some women report that exercise is also helpful. Severe menstrual cramps, particularly if paired with excessive bleeding or passage of large blood clots, can occasionally be a sign of endometriosis or other disorders of the female reproductive tract. Also known as dysmenorrhea.
