foamyoudaoicibaDictYouDict[foam 词源字典]
foam: [OE] Foam is an ancient word, with several relatives widespread among the Indo-European languages, all denoting generally ‘substance made up of bubbles’: Latin pūmex, for instance, from which English gets pumice, and probably Latin spūma, from which we get spume [14]. These and other forms, such as Sanskrit phénas and Russian pena ‘foam’, point to a common Indo-European source *poimo-, which produced prehistoric West Germanic *faimaz – whence English foam.
=> pumice, spume[foam etymology, foam origin, 英语词源]
foam (n.)youdaoicibaDictYouDict
Middle English fom, fome (c. 1300), from Old English fam "foam, saliva froth; sea," from West Germanic *faimo- (cognates: Old High German veim, German Feim), from PIE root *(s)poi-mo- "foam, froth" (cognates: Sanskrit phenah; Latin pumex "pumice," spuma "foam;" Old Church Slavonic pena "foam;" Lithuanian spaine "a streak of foam"). The plastic variety used in packaging, etc., so called from 1937.
foam (v.)youdaoicibaDictYouDict
Old English famgian "to emit foam, to boil," from the source of foam (n.). Sense of "become foamy, to froth" is from late 14c. Transitive sense is from 1725. Related: Foamed; foaming.