Definition

Noun: - The property of a material that prevents light from passing through it; the degree to which a substance is not transparent or translucent. This term specifically describes the physical characteristic of a substance that blocks, absorbs, or scatters light, making objects behind it invisible or unclear. It is the state of being opaque to visible light.

Usage

• As a subject: The of the glass was increased by adding a dark tint.
• As an object: Scientists measured the material's to determine its suitability for the lens.
• With modifiers: The high of the metal plate makes it perfect for a light shield.

Examples

• The of the fog made driving extremely hazardous.
• A material's is a key factor in designing window treatments for energy efficiency.
• The experiment required a filter with variable to control the light intensity.

Advanced Usage

• In scientific contexts: In physics and astronomy, is a critical parameter for understanding the transfer of radiation through mediums like stellar atmospheres or planetary nebulae.
  • The model calculates the star's luminosity based on the gas cloud's optical opacity.

Variants and Related Words

• Opaque (adj): Describing a material that has high optical opacity; not allowing light to pass through.
  • The bathroom window was made of opaque glass.
• Opacity (noun): The more general term for the condition of lacking transparency, which can be applied to contexts beyond light (e.g., opacity of meaning). is a specific type of opacity.
  • The report was criticized for its bureaucratic opacity.

Synonyms

• Imperviousness (to light): The quality of not allowing light to penetrate.
• Light-blocking ability: A descriptive phrase for the same property.

Antonyms

• Transparency: The property of allowing light to pass through so that objects behind can be seen clearly.
• Translucency: The property of allowing light to pass through diffusely; semi-transparency.

Noun

1. opacity to light