Origin and history of up-

"to or toward a point or place higher than another," Old English up, uppe, from Proto-Germanic *upp- "up," from PIE root *upo "under," also "up from under," hence also "over." As a preposition, from late Old English as "down onto, above and touching, sitting on, at the summit of;" from c. 1200 as "to a higher place."

Often used elliptically for go up, come up, rise up, etc. To be up to (something) "engaged in some activity" (typically reprehensible) is by 1837. Slang up the river "in jail" is recorded by 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 (n.2)) is attested by late 19c.

From the same Proto-Germanic source are 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."

c. 1200, upholden, "support, sustain" someone or something physically, from up (adv.) + hold (v.). The sense of "maintain, guarantee" (a statement, a fact) is by 1520s; the meaning "maintain in good condition or repair" is from 1570s. Compare hold-up. Related: Upheld; upholding; upholder. Similar formation in Old Frisian upholda, Middle Dutch ophouden, German aufhalten.