The Collaborative International Dictionary of English v.0.48:
Stomatitis \Stom`a*ti"tis\, n. [NL., fr. Gr. sto`ma, -atos, mouth + -itis.] (Med.) Inflammation of the mouth. [1913 Webster]WordNet (r) 3.0 (2006):
stomatitis n 1: inflammation of the mucous membrane of the mouth