Smut/smʌt/ Definition 1 of 4Pro Tip 1/3Casual Cleaning Used when casually mentioning a small, possibly insignificant amount of dirt. She flicked a bit of smut off her desk without a second thought. Pro Tip 2/3Minimal Attention Suggests a non-serious issue, generally requires simple action to remove. Noticing some smut on his shoes, he quickly wiped it off. Pro Tip 3/3Visual Notice Usually visible against the background, drawing attention to the dirt or mark. The smut stood out on the white couch, prompting her to clean it.