With the control stick neutral, tap the Shield button in midair to air-dodge. Renders fighter briefly intangible as they drift along their normal airborne arc. There’s vulnerable lag after an air dodge’s intangible frames and before the fighter can act again in midair. Air-dodging just before landing adds a little extra landing lag, but not much. See also directional air dodge and defense.
Super Smash Bros. Ultimate eGuide Ultimate Glossary of Terms and Mechanics