adnoun

plural adnouns

1. grammarAn adjective used as a noun (sensu stricto); an absolute adjective (nominalized adjective).
2. datedgrammarAny adjective.

   3. An adjective or adnoun, expresses a particular quality ascribed to a substantive—A good man, a bad man, a studious man, a lazy man—The words good, bad, studious, and lazy, express the particular quality which belong to such or such a man.

   1830, Thomas Nugent & J. Quiseau, A new Pocket Dictionary of the French and English Languages. In two Parts. 1. French and English.—2. English and French. Containing all the Words in general Use, and authorized by the best Writers. The Fifth American, from the last London Edition, Philadelphia, p.xii ("Section II: Of Grammar in general)")