hitherto

The adverb is derived from Middle English hiderto (“to the present time, until now; up to this point”), from hider (“in this direction, to or toward this place; up to the present time, until now”) (from Old English hider (“to here, hither”)) + to (“in the direction of, toward; etc.”). By surface analysis, hither +‎ to.

The adjective is derived from the adverb.