upskirt adj.

Old English up, uppe, from Proto-Germanic *upp- "up" (source also of 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 "under," also "up from under," hence also "over."

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) is attested by late 19c.

early 14c. (mid-13c. as a surname), "lower part of a woman's dress," the part that hangs from the waist, from Old Norse skyrta "shirt, a kind of kirtle;" see shirt, which is from the Old English cognate, and from which it is not always distinguishable in early use.

The sense development from "shirt" to "skirt" is obscure; it could be from the long shirts of peasant garb (compare Low German cognate Schört, in some dialects "woman's gown").

Also "lower part of a man's gown, clerical vestment, etc." (late 14c.). The sense of "border, edge, part of anything furthest from the mass or the center" (in outskirt, etc.) is recorded by late 15c.

Metonymic use for "women collectively" is from 1550s; the slang sense of "young woman" is from 1906; skirt-chaser is attested by 1942.