Where does “scumbreath” come from?

scumbreath (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 “scumbreath”, step by step

scumbreath 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 breath

StepLanguageWordMeaning
1EnglishbreathThe act or process of breathing; A single act of...
2Middle Englishbreethbreath
3Old Englishbrǣþodor, scent, stink, exhalation, vapor
4Proto-Germanicbrēþizvapour; steam; breath; odour, smell
5Proto-Indo-Europeanbʰrē-t-exhalation from heat; steam
6Proto-Indo-Europeanbʰer-to bear, carry
Every word from Proto-Indo-European (s)kewH-Every word from Proto-Germanic skūmazEvery word from Frankish skūm