n.
Pronunciation: ō - ' pa-s ə -t ē
Function: noun
Inflected Form: plural -ties
Etymology: Middle French opacité shadiness, from Latin opacitat-, opacitas, from opacus shaded, dark
Date: 1560
1 a : obscurity of sense : UNINTELLIGIBLENESS 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 (as the lens of the eye)