What is the meaning of Revelation 18:21?

* The two F.O.G. Bibles & Commentary below are currently a work in progress.

Then a mighty angel picked up a stone the size of a great millstone and cast it into the sea, saying: “With such violence the great city of Babylon will be cast down, never to be seen again.

Berean Standard Bible (BSB)

A mighty angel took up a stone like a great millstone and cast it into the sea, saying, “Thus with violence will Babylon, the great city, be thrown down, and will be found no more at all.

World English Bible (WEB)

And{G2532} a{G1520} mighty{G2478} angel{G32} took up{G142}{(G5656)} a stone{G3037} like{G5613} a great{G3173} millstone{G3458}, and{G2532} cast{G906}{(G5627)} it into{G1519} the sea{G2281}, saying{G3004}{(G5723)}, Thus{G3779} with violence{G3731} shall{G906} that great{G3173} city{G4172} Babylon{G897} be thrown down{G906}{(G5701)}, and{G2532} shall be found{G2147}{(G5686)} no more{G3364} at all{G2089}.

Strong's King James

(21) One mighty angel took up a stone like a great millstone and threw into the sea, saying, "So will Babylon, the great city be thrown down in a violent rush and won't be found still."

The F.O.G*

[21] Then a mighty messenger picked up a boulder the size of a huge millstone, hurling it into the sea, declaring: "With such violence, the great city Babylon will be thrown down, never to rise again!

The F.O.G Paraphrase

And one strong messenger did take up a stone as a great millstone, and did cast it to the sea, saying, ‘Thus with violence shall Babylon be cast, the great city, and may not be found any more at all;

Young's Literal Translation