Noah Webster's Dictionary (adv.) In a manner to excite horror; dreadfully; terribly.

Multi-Version Concordance Horribly (3 Occurrences) Jeremiah 2:12 Be astonished, you heavens, at this, and be horribly afraid. Be very desolate, says Yahweh. (WEB KJV JPS ASV WBS) Ezekiel 27:35 All the inhabitants of the islands are astonished at you, and their kings are horribly afraid; they are troubled in their face. (WEB JPS ASV DBY NAS RSV) Ezekiel 32:10 Yes, I will make many peoples amazed at you, and their kings shall be horribly afraid for you, when I shall brandish my sword before them; and they shall tremble at every moment, every man for his own life, in the day of your fall. (WEB KJV JPS ASV DBY WBS NAS)