From The Columbia Encyclopedia
In English, part of speech of vast semantic range. It can be used to name a person, place, thing, idea, or time. It generally functions as subject, object, or indirect object of the verb in the sentence, and may be distinguished by a number of formal criteria. A noun may be recognized by inflection (e.g., -'s and -s) or by derivation (e.g., -ness, -ity, and -tion).