# Compression

#### Pronunciation

**IPA:***/kɒm.prɛʃ.ən/*- Rhymes: -ɛʃən

#### Origin

From *Middle French* __compression__, from *Latin* __compressio__.

## Full definition of compression

#### Noun

#### compression

(*plural*)

**compressions**- an increase in density; the act of compressing, or the state of being compressed; compaction
- the cycle of an internal combustion engine during which the fuel and air mixture is compressed
- (
*computing*) the process by which data is compressed - Due to the presence of long-range correlations in language 21, 22 it is not possible to compute accurate measures of the entropy by estimating block probabilities directly. More efficient nonparametric methods that work even in the presence of long-range correlations are based on the property that the entropy of a sequence is a lower bound to any lossless compressed version of it 15. Thus, in principle, it is possible to estimate the entropy of a sequence by finding its length after being compressed by an optimal algorithm. In our analysis, we used an efficient entropy estimator derived from the Lempel-Ziv
**compression**algorithm that converges to the entropy 19, 23, 24, and shows a robust performance when applied to correlated sequences 25 (see Materials and Methods). - (
*music*) the electronic process by which any sound's gain is automatically controlled