SG Heritage Dictionary

Opacity [Noun] Webster's Dictionary 1828

1. Opakeness; the quality of a body which renders it impervious to the rays of light; want of transparency. opacity may exist in bodies of any color.

2. Darkness; obscurity.

Opacity [Noun] Webster's Dictionary 1913

1. The state of being opaque; the quality of a body which renders it impervious to the rays of light; want of transparency; opaqueness.

2. Obscurity; want of clearness.