Hitherto, adv.
1. To this place; to a prescribed limit. Hitherto shalt thou come, but no further. Job xxxviii. 11.
2. Up to this time; as yet; until now. The Lord hath blessed me hitherto. Josh. xvii. 14.
Shades of meaning
Fernald has no entry of its own for hitherto; he lists it under yet.
He lists it without comment; the entries above explain its neighbors.