'Reserved' in the Bible

For if God didn't spare angels when they sinned, but cast them down to Tartarus, and committed them to pits of darkness, to be reserved for judgment;

These are wells without water, clouds driven by a storm; for whom the blackness of darkness has been reserved forever.

But the heavens that now are, and the earth, by the same word have been stored up for fire, being reserved against the day of judgment and destruction of ungodly men.