'Noun' definitions:

Definition of 'noun'

(from WordNet)
noun
A content word that can be used to refer to a person, place, thing, quality, or action
noun
The word class that can serve as the subject or object of a verb, the object of a preposition, or in apposition

Definition of 'Noun'

From: GCIDE
  • Noun \Noun\ (noun), n. [OF. noun, nun, num, non, nom, F. nom, fr. L. nomen name. See Name.] (Gram.) A word used as the designation or appellation of a creature or thing, existing in fact or in thought; a substantive. [1913 Webster]
  • Note: By some grammarians the term noun is so used as to include adjectives, as being descriptive; but in general it is limited to substantives. [1913 Webster]