compression

noun

1. 1

   An increase in density; the act of compressing, or the state of being compressed; compaction.

2. 2

   The cycle of an internal combustion engine during which the fuel and air mixture is compressed.

3. 3

   The process by which data is compressed.

4. 4

   The electronic process by which any sound's gain is automatically controlled.

5. 5

   The deviation of a heavenly body from a spherical form.