Etymology: Identical with Middle Low German schûm (masculine) (Middle Swedish, Swedish, Norwegian, Danish skum), Middle Dutch schuum (masculine), neuter, schûme, feminine (Dutch schuim neuter), Old High German scûm (masculine) (Middle High German schûm, modern German schaum) < Germanic *skūmo-, < Germanic and Indogermanic root *skeu- to cover. The Germanic word was adopted in Romance as Old French escume (modern French écume), Provençal escuma, Spanish escuma, Portuguese escuma, Italian schiuma. For the shortening of the vowel (which, as the spelling scome shows, had taken place already in the 14th cent.), compare thumb, plum. The proximate source is uncertain. The word cannot represent an Old English *scúm, which would have given an initial sh. The locality of the early quots. does not favour adoption < Scandinavian, and the word is not found in Old Norse, the modern Scandinavian form being probably < Low German. The modern English form cannot well come from the Old French, though that may have been the source of the Middle English scume, assuming that the u represents the sound /yː/. Possibly the form adopted < Old French may have been replaced by one imported from Middle Dutch or Middle Low German as a term of brewing or some other industry.

Etymology: < scum n. Compare Old High German scûmen (Middle High German schûmen , modern German schäumen ), Middle Low German, Middle Dutch schûmen (modern Dutch schuimen ), Danish skumme , Norwegian skuma , Swedish skumma ; also Old French escumer (modern French écumer ) and skim v.