Where does “mustarousku” come from?

mustarousku (Finnish) comes from Finnish rousku, from Finnish -u, from Proto-Finnic -u — Forms nouns from adjectives, nouns.

mustarousku (Finnish): ugly milk-cap

Definitions

  1. ugly milk-cap

Ancestry of “mustarousku”, step by step

mustarousku traces back through two separate lines of ancestry.

via Finnish rousku

StepLanguageWordMeaning
1FinnishrouskuA milk-cap
2Finnish-uForms nouns from verbs. Most common with "e"- and...
3Proto-Finnic-uForms nouns from adjectives, nouns

via Finnish musta

StepLanguageWordMeaning
1Finnishmustablack; black horse; Elative singular form of...
2Finnish-ntääFront vowel variant of -ntaa
Every word from Proto-Finnic -u →Every word from Finnish -u →Every word from Finnish rousku →