ADJECTIVE, Noun Adjective, or ADNOUN, in Grammar, a kind of noun joined with a noun substantive, either expressed or understood, to show its manner of being, that is, its qualities or accidents. See NOUN, etc.

The word is formed from the Latin "adjicere," meaning "to add to"; as it is meant to be added to a substantive, without which it has no precise signification at all.

Father Bouvier defines adjective in a new manner and sets it in a light different from that of other grammarians.Nouns, according to him, are substantives when the objects which they represent are considered simply and in themselves, without any regard to their qualities: On the contrary, they are adjectives when they express the quality of an object. See QUALITY.

Thus, when I say simply, "a heart," the word "heart" is a substantive because none of its qualities are expressed;but when I say "a generous heart," the word "generous" is an adjective; because it adds a quality or attribute to the heart.

Adjectives, then, seem to be nothing else but modificatives.In effect, the end of an adjective being only to express the qualities of an object; if that quality is the object itself, which we speak of, it becomes a substantive;e.g., If I say, "this book is good," "good" here is an adjective.But if I say, "Good is always to be chosen," it is evident "Good"is the subject I speak of; and consequently, "Good" there is a substantive.

On the contrary, it often happens in other languages, and sometimes in our own, that a substantive becomes an adjective; as for instance, in these words, "The king, hero as he is, remembers he is a man." Where the word "hero,"though ordinarily a substantive, is yet apparently an adjective.

From this new idea of an adjective, it appears that many of the nouns which, in the common grammars, are accounted substantives are really adjectives, and vice versa;grammar, in this and a thousand other instances, depending upon custom. See SUBSTANTIVE.