n. The character of being filthy; filthiness; dirtiness; filthy habits or condition.n. Disgusting taste; nauseousness.n. Disagreeableness; unpleasantness: as, the general nastiness of the weather.n. Meanness; dishonorableness: as, the nastiness of the trick.n. That which is filthy; filth.n. Moral filth or filthiness; grossness or indecency; obscenity.n. Synonyms Foulness, defilement, pollution.