Lightproof

Part of speech: adjective

Definitions

1. Having the quality to completely block light from entering Designed to create an environment where no light can be transmitted Fabricated to ensure total opacity against light penetration
2. Capable of preventing any light from passing through a material or surface
3. Constructed to block out all light, creating a fully shaded or darkened space

Etymology: "Lightproof" is a plain compound: "light" joined to "-proof," the suffix meaning "impervious to" or "resistant to," as in "waterproof" or "bulletproof." The sense is straightforward: something that keeps light out entirely. The first half descends from an ancient root meaning "to shine," which reached English as Old English "lēoht" and became modern "light." The second half, "proof," came into English from Old French "prove" and originally meant a test or trial of something's quality, only later coming to mean resistance to a thing. Joined together, the pair describes a material or construction that has passed the test of blocking light.