Opacify

Part of speech: verb

Definitions

1. To render a material unable to transmit light, thereby making it opaque or clouded, while also transforming its visibility from clear to obscured states
2. To cause a substance to lose its transparency and become cloudy or obscure light passage
3. To change a clear or translucent material so it no longer allows light to pass through easily

Etymology: "Opacify" is a back-formation: English speakers took the noun "opacification" and carved a shorter verb from it, the way one might shorten "television" into "tele" in reverse logic. The noun came first, built on Latin "opacus," meaning "shaded" or "dark," and the verb simply reverses that process into a single action. The root "opacus" is the source of the English adjective "opaque," which came with its own sense of blocking light. Adding the suffix "-ify," which turns a stem into the sense of "make," gives "opacify" its plain meaning: to make something less transparent, or to cloud it over.

Synonyms: cloud, darken, obscure, dim, block

Antonyms: clarify, illuminate, enlighten, brighten, reveal