excrescent

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. [ 1913 Webster ]

Expunge the whole, or lip the excrescent parts. Pope. [ 1913 Webster ]

Excrescent letter (Philol.), a letter which has been added to a root; as, the d in alder (AS. alr) is an excrescent letter. [ 1913 Webster ]