bean (n.)youdaoicibaDictYouDict[bean 词源字典]
Old English bean "bean, pea, legume," from Proto-Germanic *bauno (cognates: Old Norse baun, Middle Dutch bone, Dutch boon, Old High German bona, German Bohne), and related to Latin faba "bean;" Greek phakos "lentil;" Albanian bathë "horse-bean;" Old Prussian babo, Russian bob "bean," but the original form is obscure; perhaps from a PIE reduplicated base *bha-bha-

As a metaphor for "something of small value" it is attested from c. 1300. Meaning "head" is U.S. baseball slang c. 1905 (in bean-ball "a pitch thrown at the head"); thus slang verb bean meaning "to hit on the head," attested from 1910.

The notion of lucky or magic beans in English folklore is from the exotic beans or large seeds that wash up occasionally in Cornwall and western Scotland, carried from the Caribbean or South America by the Gulf Stream. They were cherished, believed to ward off the evil eye and aid in childbirth.

Slang bean-counter "accountant" recorded by 1971. To not know beans (American English, 1933) is perhaps from the "of little worth" sense, but may have a connection to colloquial expression recorded around Somerset, to know how many beans make five "be a clever fellow."[bean etymology, bean origin, 英语词源]
wash (v.)youdaoicibaDictYouDict
Old English wascan "to wash, cleanse, bathe," transitive sense in late Old English, from Proto-Germanic *watskan "to wash" (cognates: Old Norse vaska, Middle Dutch wasscen, Dutch wassen, German waschen), from stem *wed- "water, wet" (see water (n.1)). Related: Washed; washing.

Used mainly of clothes in Old English (the principal verb for washing the body, dishes, etc. being þwean). Old French gaschier "to stain, soil; soak, wash" (Modern French gâcher) is from Frankish *waskan, from the same Germanic source. Italian guazzare also is a Germanic loan-word. To wash (one's) hands of something id 1550s, from Pilate in Matt. xxvii.24. To wash up "clean utensils after a meal" is from 1751. Washed up "no longer effective" is 1923, theater slang, from notion of washing up at the end of a job.