Source : Webster's Revised Unabridged Dictionary (1913)

Prolapse \Pro*lapse"\, n. [L. prolapsus, fr. prolapsus, p. p. of
   prolabi to fall forward; pro forward + labi to glide, fall.]
   (Med.)
   The falling down of a part through the orifice with which it
   is naturally connected, especially of the uterus or the
   rectum. --Dunglison.

Prolapse \Pro*lapse"\, v. i.
   To fall down or out; to protrude.

Source : WordNet®

prolapse
     n : the slipping or falling out of place of an organ (as the
         uterus) [syn: {prolapsus}, {descensus}]
     v : slip or fall out of place, as of body parts; "prolapsed
         rectum"