The story
- Proto-Indo-European · derived from*skew-“to cover, conceal”
- Proto-Germanic · derived from*skūmaz“foam”
- Frankish · derived from*skūm“froth, foam”
- Old French · derived fromescumer“to remove scum”
- Middle English · inherited fromskemen
- English todayskim
From Middle English skemen, skymen, variants of scumen, from Old French escumer (“to remove scum”), from escume (“froth, foam”), from Frankish *skūm (“froth, foam”), from Proto-Germanic *skūmaz (“foam”), from Proto-Indo-European *skew- (“to cover, conceal”). See scum.
Etymology from Wiktionary, CC BY-SA 4.0.