Occludant

Part of speech: adjective, noun

Definitions

1. Something, such as a substance or agent, that blocks or closes off an opening, passage, or surface
2. An agent or material that obstructs a passage or covers an opening so that it is shut off
3. Any substance or device that acts to close, block, or seal off a channel, pore, or aperture

Etymology: "Occludant" is a near-synonym of "occlusive," and its history runs through the same Latin verb. The source word is Latin "occlūsīvus," an adjective built from "occlūdere," "to shut up" or "to close off," which combines "ob-" ("against, in the way") with "claudere," "to close." The root "claudere" also gave English "close," "include," and "conclude," so the family of words shares a common idea of shutting something in or out. Medical and scientific writers have drawn on this sense of closing or blocking. A thing that is occlusive stops a passage, whether a blood vessel, a gap, or a surface. "Occludant" follows the same pattern, offering a different ending for the same underlying meaning of closing something off.

Synonyms: occlusive