"permanent disappearance" is correct and usable in written English
You can use it in situations where something or someone has vanished or gone away permanently. For example, "The population of the island had seen a permanent disappearance over the span of a few years."
And who benefits from the immigrants' temporary or perhaps permanent disappearance from the area?
Several extinction events caused the permanent disappearance of half of Earth's known biological families.
Could the boy's permanent disappearance have something to do with his sister's determination to starve herself?
A FAQ provides some grief counselling, as the death of a game means the permanent disappearance of a world, its characters and all the relationships forged within it.
For years, the Florida panther, a majestic creature that lurks in and around the forests of the Everglades, has teetered on the edge of permanent disappearance.
The loss of every individual brings their species ever closer to utter and permanent disappearance.
Permanent, extrajudicial disappearance was apparently preferable to letting the prisoner ever tell what had been done to him.
A black-winged stilt, which acquired the nickname "Sammy", arrived in 1993 and became a permanent resident up to its disappearance in 2005.
A black-winged stilt, which acquired the nickname "Sammy", arrived at Titchwell in 1993 and became a permanent resident up to its disappearance in 2005.
Some lower-court judges are side-stepping it by interpreting disappearances as a "permanent" kidnapping offence, but Ms Reyna thinks this could be overturned by the Supreme Court.
Trump's administration has faced mounting criticism over its response (or lack thereof) to the disappearance of Khashoggi, a permanent U.S. resident and vocal critic of the Saudi royal family in his columns for the Washington Post.
