What are hypersonic missiles?

Hypersonic missiles, by definition, fly at least 5 times the speed of sound (Mach 5), can fly at up to 10 times the speed of sound, and can maneuver in mid-flight, making it harder for air-defense systems to intercept. Russia has said it has twice deployed its newest Kinzhal (Dagger) hypersonic missile in Ukraine, claiming on March 20, 2022, to have destroyed a fuel depot near Mykolaiv and an underground ammunition storage site in the west.