'Reserved' in the Bible

For if God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;

These are wells without water, clouds that are carried with a tempest; to whom the mist of darkness is reserved for ever.

But the heavens and the earth, which are now, by the same word are kept in store, reserved unto fire against the day of judgment and perdition of ungodly men.