noun, masculine/fle.o/plural: fléaux
a flail, either tool or weapon; a scourge; a curse, a calamity or a plague; the beam of a mechanical balance
“La haine en ligne est un fléau d’une immense ampleur.” — Online hatred is a scourge of immense scale.
Inherited from Old French flaiel, flael, flayau, inherited from Latin flagellum.