The Collaborative International Dictionary of English v.0.48:

Procidence \Proc"i*dence\, Procidentia \Proc*i*den"ti*a\,, n.
   [L. procidentia, fr. procidens, p. pr. of procidere to fall
   down forward.] (Med.)
   A falling down; a prolapsus. [R.] --Parr.
   [1913 Webster]