vi·sor / ˈvīzər/ (also vi·zor) • n. a stiff brim at the front of a cap. ∎ a movable part of a helmet that can be pulled down to cover the face. ∎ a screen for protecting the eyes from unwanted light, esp. one at the top of a vehicle windshield. ∎ hist. a mask. DERIVATIVES: vi·sored adj.