mephitic /ˌmɛˈfɪ.tɪk/ adjective1 •Foul-smelling or noxious, particularly of a gas or atmosphere."I could have borne the sight of his crutch," said she, "but the crutch and the nephew together really oppress me like a mephitic vapour." — 1842 formsmore mephitic · most mephitic