Name for balls of dirt made by rubbing hands

single-word-requests

How about dregs, smut, or crud?

dregs: a small remnant; any small quantity.

crud: a deposit or coating of refuse or of an impure or alien substance; muck.

smut: a speck of soot or dirt.

Related

(Metaphorical) meaning of "lowercase"
Why is the Australian Labor Party spelt without a 'u'? [closed]
Words where "not [word]" means more than a lack of
Spelling of word meaning small bit of lint-like detritus
Is 'folk' a politically correct substitute for 'people'?
Is there a well-known secular sentence that uses all three of the imperative, indicative, and subjunctive moods?
Is there a word or phrase for drinking from a cup which is full without lifting it?
Umbrella term for “penalty” and “bonus”
What is the linguistic term to describe “–“ part of the phrase in “He ‘lied his a– off”?
Is there a technical term for words that can denote both activity and its result?
Is there a linguistic term for words that mean "not a member of a certain group"?
Might the word "hushpuppy" be a corruption of a Native American word?