crumbyoudaoicibaDictYouDict[crumb 词源字典]
crumb: [OE] Relatives of crumb are fairly widespread in the Germanic languages – German has krume, for example, and Dutch kruim – and it is represented in some non- Germanic Indo-European languages, such as Greek grūméā and even Albanian grime. As these forms indicate, the b is not original (the Old English word was cruma); it first appeared in the 16th century, but crum remained an accepted spelling well into the 19th century. The derivative crumble appeared in the 16th century.
=> crumble[crumb etymology, crumb origin, 英语词源]
crumb (n.)youdaoicibaDictYouDict
Old English cruma "crumb, fragment," from a West Germanic root of obscure origin (compare Middle Dutch crume, Dutch kruim, German krume). The -b- appeared mid-15c., in part by analogy with words like dumb, in part perhaps reinforced by crumble. Slang meaning "lousy person" is 1918, from crumb, U.S. slang for "body-louse" (1863), so called from resemblance.