Anything that makes things not visible, hidden. Either in the sense of blindness, concealment or in the sense of protection (also see definition for “Light/Lamp/Brightness“).
- Darkness used for blindness (making not visible)
Acts 13:11 (KJV) And now, behold, the hand of the Lord is upon thee, and thou shalt be blind, not seeing the sun for a season. And immediately there fell on him a mist and a darkness; and he went about seeking some to lead him by the hand.
- Darkness used for ignorance (not mentally visible)
Psalms 82:5 (KJV) They know not, neither will they understand; they walk on in darkness: all the foundations of the earth are out of course.
Ephesians 4:18 (KJV) Having the understanding darkened, being alienated from the life of God through the ignorance that is in them, because of the blindness of their heart:
- Darkness used as hiding something and opposite of light.
1 Corinthians 4:5 (KJV) Therefore judge nothing before the time, until the Lord come, who both will bring to light the hidden things of darkness, and will make manifest the counsels of the hearts: and then shall every man have praise of God.
- Shadow used synonymously with secret.
Psalms 91:1 (KJV) He that dwelleth in the secret place of the most High shall abide under the shadow of the Almighty.
- Shadow used as protection (hidden, protected).
Psalms 17:8 (KJV) Keep me as the apple of the eye, hide me under the shadow of thy wings.
- Shadow used for symbols (a symbol hides the true meaning of something).
Colossians 2:16-17 (KJV) Let no man therefore judge you in meat, or in drink, or in respect of an holyday, or of the new moon, or of the sabbath days:  Which are a shadow of things to come; but the body is of Christ.