A heretofore unknown side of his milk brother was being revealed to Bernardo.

Reith is amazed to find men on a heretofore unknown, distant planet.

The most exciting thing that can happen to a paleontologist is to discover a heretofore unknown species.

He was seized by a heretofore unknown majestic feeling of true freedom.

The message below purports to come from a heretofore unknown group, with an unpronounceable name.

Aari realized almost immediately the problem with demanding to be taken to the leader of a species heretofore unknown to you.

His rival, heretofore unknown, came over and cursed at him.

Now he was alert to the possibility that some secret technology, heretofore unknown to him, had been employed.

Her voice was edged with something heretofore unknown to her; a human would have called it anger.

The rare breed of dog was heretofore unknown to most Americans.