crud

1. Dirt, filth or refuse. (uncountable)
2. Something of poor quality. (figuratively, uncountable)
3. A contemptible person. (countable)
4. Mixed impurities, especially wear and corrosion products in nuclear reactor coolant. (countable, uncountable)
5. A heavy wet snow on which it is difficult to travel. (uncountable)
6. Feces; excrement. (uncountable)
7. Venereal disease, or (by extension) any disease. (US, slang, uncountable)
8. A fast-paced game, loosely based on billiards or pool, with many players participating at the same time. (uncountable)

Plural cruds