n. - The driving of one fragment of bone into another so that
the fragments are not movable upon each other; as, impaction of the
skull or of the hip.
n. - An immovable packing; (Med.), a lodgment of something in
a strait or passage of the body; as, impaction of the fetal head in the
strait of the pelvis; impaction of food or feces in the intestines of
man or beast.