What does 'first estate' mean in Jude 1:6 (KJV)?

Those angles probably are the ones that are talked about in Gen. 6 that went into the daughters of men" God never intended for Angeles to mate with humans " so in Jude were it States those Angeles which kept not their first estate " (meaning the purpose in Which God created them even the power they possessed " they used it not in the manner and which God created them to..

These verses looks like refer to fall of angels.

NIV renders the verse like this: Jude 1:6 "And the angels who did not keep their positions of authority but abandoned their proper dwelling—these he has kept in darkness, bound with everlasting chains for judgment on the great Day.". So it is clear that it is describing those angels.

So i think, "first estate" in KJV is the position of authority God granted to a group of angels who misused it and was thrown out. I believe the same thing referred here in Isaiah 14:12-15.

"How you have fallen from heaven, morning star, son of the dawn! You have been cast down to the earth, you who once laid low the nations! You said in your heart, “I will ascend to the heavens; I will raise my throne above the stars of God; I will sit enthroned on the mount of assembly, on the utmost heights of Mount Zaphon.[a] I will ascend above the tops of the clouds; I will make myself like the Most High.” But you are brought down to the realm of the dead, to the depths of the pit. "

KJV uses "O Lucifer, Son of the morning"

I was reading in the Apocrypha and found something referring to the first estate in 1 Adam and Eve. This book was likely written around the 5th or 6th century AD and was first translated into English in 1882. 1 Adam and Eve 5:7 "But the wicked Satan who continued not in his first estate, nor kept his faith; in whom was no good intent towards Me, and who though I had created him, yet set Me at naught, and sought the Godhead, so that I hurled him down from heaven,--he it is who made the tree appear pleasant in your eyes, until you ate of it, by hearkening to him. 1 Adam and Eve 55:7-15 gives more details and is worth reading if you have the time to look it up. It is similar to Revelations 12. Satan and his followers were hurled down to Earth and are executing a backup plan. This is to make war against the righteous, to tempt and deceive man. Revelations 12:17 And the dragon was wroth with the woman, and went to make war with the remnant of her seed, which keep the commandments of God, and have the testimony of Jesus Christ.

Their habitation was heaven their first estate was obeying God and not to marry.

But they did something that the other angels did not do that got them locked away till the judgement.

They may be the ones in Gen 6 that took earthly women to marry and had children by them.

Revelation chapter 12 says there was a war in heaven.

Revelation 12:7-9 (NKJV)
⁷  And war broke out in heaven: Michael and his angels fought with the dragon; and the dragon and his angels fought, ⁸  but they did not prevail, nor was a place found for them in heaven any longer. ⁹  So the great dragon was cast out, that serpent of old, called the Devil and Satan, who deceives the whole world; he was cast to the earth, and his angels were cast out with him.

Satan and his angels, fought Michael and his angels, but could not win.

Before that, it said that Satan's tail swept a third of the stars.

Revelation 12:4 (NKJV)
⁴  His tail drew a third of the stars of heaven and threw them to the earth. And the dragon stood before the woman who was ready to give birth, to devour her Child as soon as it was born.

meaning 1/3 of the angelic host fell with him in his rebellion, for they rebelled also. Thus scripture lets us know that they were thrown out with Satan, losing their First Estate. If they weren't chained in prison, they would be creating havoc among the people of the Earth. Thank God for this!

Looking at Blue Letter Bible, here "first estate" is written as archē (Strong's G746). The fifth definition is:

5) the first place, principality, rule, magistracy
a) of angels and demons

Thus, it would seem that the angels left where they were supposed to be, and as such, were cast out. This is made clear by the NLT version of the same verse:

Jude 1:6 (NLT)
And I remind you of the angels who did not stay within the limits of authority God gave them but left the place where they belonged. God has kept them securely chained in prisons of darkness, waiting for the great day of judgment.

[Emphasis mine.]

Hence, these angels were told by God where to be, but they rebelled against God's authority and as such were put into Hell.