opacity

English

Etymology

From opaque +‎ -ity, from French opacité, from Latin opacitas.

Pronunciation

• (US) enPR: ōpăsʹĭti, IPA^(key): /oʊˈpæsɪti/

• Audio (US):

  (file)

Noun

opacity (countable and uncountable, plural opacities)

1. (uncountable) The state or quality of being opaque, not allowing light to pass through.

   We could not see the sandbar due to the opacity of the muddy water.

2. (uncountable) The state or quality of being inaccessible to understanding.

   The opacity of these decisions is troubling.

3. (optics, countable) A measure of relative impenetrability to electromagnetic radiation such as light.

   The opacity of a clean glass window is near zero.

4. (countable) An opaque area.
   • 1968, Dark A. J., Kirkham T. H., “Congenital corneal opacities in a patient with Rieger's anomaly and Down's syndrome”, in British Journal of Ophthalmology, volume 52, number 8, →DOI, page 631:

     This report concerns a child with Down's syndrome (mongolism) and bilateral congenital corneal opacities born into a family affected through three generations by Rieger's anomaly.

   • 1992, Dick, J. A. et al., “The significance of irregular opacities on the chest roentgenogram”, in Chest, volume 102, number 1, →DOI, →PMID, pages 251-60:

     Scanty irregular opacities are not uncommonly observed on the chest roentgenogram in the absence of interstitial fibrosis of the lungs.

Synonyms

• nontransparency
• opaqueness

Coordinate terms

• transparency

Derived terms

• nonopacity
• radioopacity
• radiopacity
• referential opacity
• semiopacity
• snowball opacity
• subopacity

Translations

state of being opaque; blocking light

Belarusian: непразры́стасць f (njeprazrýstascʹ) Bulgarian: непрозрачност f (neprozračnost) Catalan: opacitat (ca) f Czech: neprůhlednost f Danish: uigennemsigtighed c, ugennemsigtighed Finnish: läpikuultamattomuus (fi), läpinäkymättömyys (fi) French: opacité (fr) f Galician: opacidade (gl) f German: Opazität (de) f, Undurchsichtigkeit f, Lichtundurchlässigkeit f Greek: αδιαφάνεια (el) f (adiafáneia) Hindi: अपारदर्शिता (hi) f (apārdarśitā) Indonesian: ketidakbeningan Latvian: necaurredzamība f, necaurspīdīgums m Norwegian: Bokmål: opasitet m, ugjennomsiktighet (no) m or f Portuguese: opacidade (pt) f Russian: непрозра́чность (ru) f (neprozráčnostʹ) Spanish: opacidad (es) f Swedish: opacitet (sv) c Tagalog: opasidad Ukrainian: непрозо́рість f (neprozóristʹ)

state of being inaccessible to understanding

Bulgarian: неясност f (nejasnost) French: opacité (fr) f German: Undurchsichtigkeit f, Nebulösität f Tagalog: opasidad

measure of relative opaqueness

Finnish: läpikuultamattomuus (fi), läpinäkymättömyys (fi) Indonesian: ketidakbeningan Tagalog: opasidad

opaque area

Ukrainian: помутні́ння n (pomutnínnja)

The translations below need to be checked and inserted above into the appropriate translation tables. See instructions at Wiktionary:Entry layout § Translations.

Translations to be checked

Swedish: (please verify) opak (sv)