The specific word translated hell here is the Greek word tartaro?. This is the only time it’s used in the Bible, and it is a verb. It only applies to fallen angels, not human beings. So, this is less a specific address and more of an action, describing the action of throwing them down to their imprisonment. The noun form is tartarus, mentioned extensively in Greek and Roman mythology. 

The fall of the angels who sinned was a fall from honor and dignity, into dishonor and condemnation. The thought seems to be: “God spared not the angels who sinned, but degraded them, and delivered them into the chains of darkness.” 

2 Peter 2:4 describes sinful angels as being in pits of darkness, reserved for judgment. Jude 1:6 tells us sinful angels did not keep their own domain (origin, order, place or rank) and are now in eternal bonds (chains, shackles) under darkness.

The disloyal and evil actions of these fallen spirit beings led to the action of God, which was to cast them out of His light and His heavenly abode into a condition of darkness and limitation. Expelled from heaven, we think they are now restrained to earth’s atmosphere.

They are restrained in chains under darkness, yet they are not completely ineffective. This indicates they are held back and limited in their abilities, yet they still have great power when dealing with the human race. They still seek to control others, just like their leader, Satan, who is still the ruler of this world (John 12:31, 14:30, 16:11).

Additional Resource:
Christian Questions Podcast
Episode #1305: “How Do Satanic Demons Influence Our World?
Establishing the origin, power and methods of dark spiritual beings
Preview Video
CQ Rewind Show Notes

5-part audio series on hellfire