Microcavity

Part of speech: noun

Definitions

1. A very small cavity or hollow space, typically formed within a material or structure and often measured at microscopic scales
2. An extremely minute empty chamber or gap, usually occurring within a solid substance or confined region at near-microscopic dimensions
3. A diminutive enclosed void or cavity at very small scale, commonly encountered in materials science and optics applications

Etymology: A microcavity is simply a small cavity: the compound joins the prefix "micro-" to "cavity." The prefix comes from Ancient Greek "mīkrós," meaning "small," and it reached English as a combining form, so it appears in many modern scientific coinages. Cavity itself has a longer road, borrowed into English from Latin "cavitas," meaning "hollowness," which grew from "cavus," "hollow." The useful thing about "micro-" is how easily it attaches to older words. Once English speakers had "cavity," which had long described any hollow space, adding "micro-" let physicists and engineers name hollows measured on a tiny scale, such as the small resonant chambers used in lasers and optical devices. The compound is a modern technical formation, so its meaning is transparent: whatever a cavity is, a microcavity is one at a very small size.