Filthy, unclean (esp. in a religious sense).
Things like cadavers or excrement are sammal, but also moral or ritual uncleanliness is sammal. People who commit illicit sex are considered sammal. A woman during her menstruation is sammal and should not cook for others, esp. for old people. If one eats anything forbidden one becomes sammal. Before doing the ablutions for worship a person is considered sammal.
That woman is unclean because she always commits adultery.