'Dark' in the Bible

And the Lord said to Moses, Let your hand be stretched out to heaven, and all the land of Egypt will be dark, so that men will be feeling their way about in the dark.

And when Moses' hand was stretched out, dark night came over all the land of Egypt for three days;

Keep it till the fourteenth day of the same month, when everyone who is of the children of Israel is to put it to death between sundown and dark.

And it came between the army of Egypt and the army of Israel; and there was a dark cloud between them, and they went on through the night; but the one army came no nearer to the other all the night.

And the people kept their places far off, but Moses went near to the dark cloud where God was.