\Ex*cres"cent\, a. [L. excresens, -entis, p. pr. of
excrescere to grow out; ex out + crescere to grow. See
{Crescent}.]
Growing out in an abnormal or morbid manner or as a
superfluity.
      Expunge the whole, or lip the excrescent parts. --Pope.
{Excrescent letter} (Philol.), a letter which has been added
   to a root; as, the d in alder (AS. alr) is an excrescent
   letter.