Dictionary entry

Till (5)

Webster's Dictionary 1913

Till (?), conj. As far as; up to the place or degree that; especially, up to the time that; that is, to the time specified in the sentence or clause following; until.

And said unto them, Occupy till I come. Luke xix. 13.

Mediate so long till you make some act of prayer to God. Jer. Taylor.

There was no outbreak till the regiment arrived. Macaulay.

☞ This use may be explained by supposing an ellipsis of when, or the time when, the proper conjunction or conjunctive adverb begin when.