opacity

noun

opac·​i·​ty ō-ˈpa-sə-tē 

plural opacities

1

a

: obscurity of sense : unintelligibility

b

: the quality or state of being mentally obtuse : dullness

2

: the quality or state of a body that makes it impervious to the rays of light

broadly : the relative capacity of matter to obstruct the transmission of radiant energy

3

: an opaque spot in a normally transparent structure (such as the lens of the eye)

Synonyms

• ambiguity
• ambiguousness
• darkness
• equivocalness
• equivocation
• inscrutability
• inscrutableness
• murkiness
• mysteriousness
• nebulosity
• nebulousness
• obliqueness
• obliquity
• obscurity
• opaqueness

Examples of opacity in a Sentence

the opacity of the glass

Critics have noted the opacity of her writing style.

Recent Examples on the Web

The keypad can be customized to easily select tools or different functions on Adobe software, while the dial can be used to control things like zoom, brush sizes or image opacity. —Megan Poinski, Forbes, 25 Sep. 2024

While the pay hike for switching jobs has fallen in recent years, current opacity over pay still inspires employees to make the change. —Christiaan Hetzner, Fortune Europe, 27 Sep. 2024

Still, burgeoning business ties with Russia come at a cost, even if that is difficult to quantify because of its opacity. —Pei-Lin Wu, Washington Post, 26 July 2024

In the letter, the agency asked the state to add more details about monitoring and recordkeeping requirements for periodic opacity monitoring. —Sarah Lapidus, The Arizona Republic, 13 Aug. 2024

Word History

Etymology

Middle French opacité shadiness, from Latin opacitat-, opacitas, from opacus shaded, dark

First Known Use

1575, in the meaning defined at sense 1a

Kids Definition

opacity

noun

opac·​i·​ty ō-ˈpas-ət-ē 

plural opacities

: the quality or state of being opaque

Medical Definition

opacity

noun

opac·​i·​ty ō-ˈpas-ət-ē 

plural opacities

1

: the quality or state of a body that makes it impervious to the rays of light

broadly : the relative capacity of matter to obstruct by absorption or reflection the transmission of radiant energy (as X-rays, infrared radiation, or sound)

2

: an opaque spot in a normally transparent structure (as the lens of the eye)