Meaning of nonword

non•word

Pronunciation: (non-wûrd'), [key]
— n.
  1. a word that is not recognized or accepted as legitimate, as one produced by a spelling or typographical error.
  2. a word whose meaning or use is not approved in a given circumstance: “Failure” is a nonword in her vocabulary.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.