Other forms: imperiled, imperilled, imperiling, imperils, imperilling
To imperil is to put something in danger. Imperil the whole project.
It is formal and takes an abstract object more often than a person. To imperil something is stronger than to risk it, since the danger is already present.
1verbimperilTo put something in danger.
“One more delay would imperil the funding altogether.”
imperil is an endangering.
From im- + peril.
Etymology from Wiktionary, CC BY-SA