Where does “scummish” come from?

scummish (English) comes from English scum, from Middle English scum, from Middle Dutch schūme, from Old Dutch *scūm, from Frankish skūm, from Proto-Germanic skūmaz, from Proto-Indo-European (s)kewH- — to cover, bedeck; cover.

Ancestry of “scummish”, step by step

scummish traces back through two separate lines of ancestry.

via English scum

StepLanguageWordMeaning
1EnglishscumA layer of impurities that accumulates at the...
2Middle Englishscum
3Middle Dutchschūmefoam
4Old Dutch*scūm
5Frankishskūmfoam; froth, foam
6Proto-Germanicskūmazfilm; grime; scum; foam; froth; yeast
7Proto-Indo-European(s)kewH-to cover, bedeck; cover

via English ish

StepLanguageWordMeaning
1EnglishishPronunciation spelling of is; somewhat,...
2English-ishTypical of, similar to, being like; Somewhat,...
3Middle English-ishAlternative form of -yssh
4Old English-isċ-ish
5Proto-West Germanic-iskCreates adjectives from nouns
6Proto-Germanic-iskazForms adjectives from nouns with the sense of...
7Proto-Indo-European-iskosCharacteristic of, typical of, pertaining to
Every word from Proto-Indo-European (s)kewH-Every word from Proto-Germanic skūmazEvery word from Frankish skūm