Quiz: Remember the definition of mal de mer?
c.1400, from Middle French compression (14c.), from Latin compressionem (nominative compressio) "a pressing together," noun of action from past participle stem of comprimere (see compress (v.)). Related: Compressional. Compressional wave is attested from 1887.
compression com·pres·sion (kəm-prěsh'ən)
The state of being compressed.
See data compression.