An Etymological Dictionary of Astronomy and Astrophysics

1. General: The extent to which something is covered.
   

2. Astro.: The total area of the sky observed in a particular → sky survey. See also → fractional sky coverage.
   

3. The area within which a radio signal sent by a transmitter is received reliably .
   

4. In film making, the shooting of a scene from various views and using various exposures.

Etymology (EN): From → cover + -age a suffix forming abstract nouns.

Etymology (PE): → cover.