A noun or name; the part of speech which designates something that exists, or some object of thought, either material or immaterial; as, the words man, horse, city, goodness, excellence, are substantives.

a noun or a pronoun that is used in place of a noun

a noun , pronoun , or any word functioning like a noun

a word or phrase that acts like a noun and has a meaning like that of a noun

a word or phrase that functions grammatically as a noun

a word or word group functioning as a noun

The broad grammatical category including nouns and nominals is called the substantives.

a noun; acutal thing