cakeyoudaoicibaDictYouDict[cake 词源字典]
cake: [13] Originally, cake was a term for a flat round loaf of bread (it is this ‘shape’ element in its meaning that lies behind more modern usages such as ‘cake of soap’). It is not until the 15th century that we find it being applied to foodstuffs we would now recognize as cakes, made with butter, eggs, and some sort of sweetening agent. English borrowed the word from Old Norse kaka; it is related to cookie (from Dutch koekje), but not, despite the similarity, to cook. The expression piece of cake ‘something easy’ seems to have originated in the 1930s.
=> cookie[cake etymology, cake origin, 英语词源]
saccharinyoudaoicibaDictYouDict
saccharin: [19] Medieval Latin saccharum ‘sugar’ belonged to the same word-family as the ancestor of English sugar. Its original contribution to English was the adjective saccharine ‘sugary’ [17]; and in the late 1870s the German chemist Fahlberg used it in coining the term saccharin for the new sweetening substance he had invented. English borrowed it in the mid 1880s.
=> sugar
sweeten (v.)youdaoicibaDictYouDict
1550s (intransitive), from sweet (adj.) + verbal ending -en (1). Transitive sense ("become sweet") is from 1620s. The Middle English form of the verb was simply sweet, from Old English swetan. Related: Sweetened; sweetening.