Answer: lightening

AnswerCrossword Clue
lighteningto make or become less heavy or burdensome
lighteningto make or become less dark
lighteningthe descent of the uterus into the pelvic cavity, occurring toward the end of pregnancy, changing the contour of the abdomen and facilitating breathing by lessening pressure under the diaphragm
lighteningLIGHTEN, to reduce the weight of