"until," Old English til (Northumbrian) "to," from Old Norse til "to, until," from Proto-Germanic *tilan (source also of Danish til, Old Frisian til "to, till," Gothic tils "convenient," German Ziel "limit, end, goal"). A common preposition in Scandinavian, serving in the place of English to, probably originally the accusative case of a noun now lost except for Icelandic tili "scope," the noun used to express aim, direction, purpose (as in aldrtili "death," literally "end of life"). Also compare German Ziel "end, limit, point aimed at, goal," and till (v.).
until prep.
c. 1200, from till (prep.). The first element is un- "as far as, up to" (also in unto), from Old Norse *und "as far as, up to," from Proto-Germanic *und- (source also of Old English oð "up to, as far as," Old Frisian, Old Saxon, Gothic und), from PIE *nti-, from root *ant- "front, forehead," with derivatives meaning "in front of, before."
The two syllables have the same meaning. Originally also used of persons and places. As a conjunction from c. 1300. Similar formation in Swedish intill, Danish indtil (northern English and Scottish formerly also had intill/intil "into, in"). The Modern German equivalent, bis (Old High German biaz), is a similar compound, of Old High German bi "by, at, to" and zu "to."