Radiopacity

Part of speech: noun

Definitions

1. The feature that indicates how well a material can obstruct radiation
2. The property of a substance that determines its capacity to prevent radiation from passing through
3. A characteristic describing how effectively a material hinders the transmission of radiation

Etymology: Radiopacity is a plain technical compound, built from the combining form "radi-", from Latin "radius" meaning ray or spoke, and the English noun "opacity", which describes the quality of being impervious to light or other rays. Put together, the word names how strongly a substance blocks rays, most often the X-rays used in medical imaging. The "radi-" element here refers to radiation rather than to the geometric radius, so the term reads literally as "ray-opacity." Its formation follows the familiar pattern of pairing a scientific prefix with an older English noun, which is why its parts are easy to recognise even though the whole is a modern coinage.

Synonyms: opacity, radio-opacity, visibility, density, non-transparency

Antonyms: radiolucency, transparency, clarity, translucence, see-through