'Gloom' in the Bible

You came near and stood at the foot of the mountain, and the mountain burned with fire to the very heart of the heavens: darkness, cloud and thick gloom.

“These words the Lord spoke to all your assembly at the mountain from the midst of the fire, of the cloud and of the thick gloom, with a great voice, and He added no more. He wrote them on two tablets of stone and gave them to me.