'Thick' in the Bible

So Moses stretched out his hand toward the sky, and for three days a thick darkness was all over the land of Egypt [no sun, no moon, no stars].

The Lord said to Moses, “Behold, I will come to you in a thick cloud, so that the people may hear when I speak with you and may believe and trust in you forever.” Then Moses repeated the words of the people to the Lord.

So it happened on the third day, when it was morning, that there were thunder and flashes of lightning, and a thick cloud was on the mountain, and a very loud blast was sounded on a ram’s horn, so that all the people who were in the camp trembled.

So the people stood at a [safe] distance, but Moses approached the thick cloud where God was.