a. Path. [ad. mod.L. aphthōs-us (Fr. aphtheux), f. APHTHA: see -OUS.] Of the nature of, or characterized by, aphtha.
1757. Whyte, in Phil. Trans., L. 572. Tongue with a beginning aphthous crust on some parts of it.
1830. Lindley, Nat. Syst. Bot., 7. Aphthous affections of the mouth.
184952. Todd, Cycl. Anat., IV. 1155/1. An aphthous tongue.