river (n.)youdaoicibaDictYouDict[river 词源字典]
early 13c., from Anglo-French rivere, Old French riviere "river, riverside, river bank" (12c.), from Vulgar Latin *riparia "riverbank, seashore, river" (source also of Spanish ribera, Italian riviera), noun use of fem. of Latin riparius "of a riverbank" (see riparian). Generalized sense of "a copious flow" of anything is from late 14c. The Old English word was ea "river," cognate with Gothic ahwa, Latin aqua (see aqua-). Romanic cognate words tend to retain the sense "river bank" as the main one, or else the secondary Latin sense "coast of the sea" (compare Riviera).

U.S. slang phrase up the river "in prison" (1891) is originally in reference to Sing Sing prison, which was literally "up the (Hudson) river" from New York City. Phrase down the river "done for, finished" perhaps echoes sense in sell down the river (1851), originally of troublesome slaves, to sell from the Upper South to the harsher cotton plantations of the Deep South.[river etymology, river origin, 英语词源]
up (adv.)youdaoicibaDictYouDict
Old English up, uppe, from Proto-Germanic *upp- "up" (cognates: Old Frisian, Old Saxon up "up, upward," Old Norse upp; Danish, Dutch op; Old High German uf, German auf "up"; Gothic iup "up, upward," uf "on, upon, under;" Old High German oba, German ob "over, above, on, upon"), from PIE root *upo "up from below" (cognates: Sanskrit upa "near, under, up to, on," Greek hypo "under, below," Latin sub "under;" see sub-).

As a preposition, "to a higher place" from c. 1500; also "along, through" (1510s), "toward" (1590s). Often used elliptically for go up, come up, rise up, etc. Up the river "in jail" first recorded 1891, originally in reference to Sing Sing, which is up the Hudson from New York City. To drive someone up the wall (1951) is from the notion of the behavior of lunatics or caged animals. Insulting retort up yours (scil. ass) attested by late 19c.