Definitions

1. verb

to remove a flag from something, especially a ship or a building

“The unflag of the old building was a sign of its new ownership.”

2. verb

to stop flying a flag

“The unflag of the national flag was a sign of respect during the mourning period.”

3. verb

to remove or cancel a signal or warning, especially on a ship or aircraft

“The crew unflagged the warning lights to signal that it was safe to land.”