fɪlθ ˈfaʊəl.nəs the attribute of having a strong offensive smell (of weather) the badness of the weather they were wearied with the foulness of the weather a state characterized by foul or disgusting dirt and refuse disgusting wickedness and immorality he understood the foulness of sin his display of foulness deserved severe punishment mouths which speak such foulness must be cleansed