You searched for: “opacity
1. The state of being opaque (not allowing the passage of light); unperceptive, dense.
2. On a radiograph, a more transparent area is interpreted as an opacity to x-rays in the body.
3. Mental dullness.
This entry is located in the following units: -acity (page 2) -ity (page 13)
opacity (s) (noun), opacities (pl)
1. A thick or dark condition that makes something; such as, glass or a liquid difficult to see through: The opacity of Shareen's windows were a result of not having the accumulation of dirt cleaned off.

Opacities represent the degrees to which light is obscured by pollutant particles in the air.

2. Having difficulty in understanding statements, presentations, or in explaining something: Students had difficulty in understanding the opacity of the teacher's scientific presentation.

The opacities of most dictionaries simply don't give people clear or straightforward definitions.

3. Etymology: "darkness, obscurity", from French opacité; from Latin opacitatem, opacitas, "shade, shadiness"; from opacus, "shaded, dark".
This entry is located in the following unit: opaqu- (page 1)
Word Entries at Get Words: “opacity
A measure of the absorption of incident radiation by a body, being the ratio of the total radiant energy incident upon a body to the amount that passes through it.
This entry is located in the following unit: Astronomy and related astronomical terms (page 17)