compression

UK: /kəmˈprɛʃ^ən/ US: /kəmˈprɛʃən/ ,(kəm presh′ən)

WordReference Random House Learner's Dictionary of American English © 2025

com•pres•sion /kəmˈprɛʃən/  n. [uncountable]

1. the act of compressing or the state of being compressed.

See -press-.

WordReference Random House Unabridged Dictionary of American English © 2025

com•pres•sion  (kəm presh′ən), n. 

1. the act of compressing.
2. the state of being compressed.
3. the effect, result, or consequence of being compressed.
4. Automotive (in internal-combustion engines) the reduction in volume and increase of pressure of the air or combustible mixture in the cylinder prior to ignition, produced by the motion of the piston toward the cylinder head after intake.
5. Computing reduction of the size of computer data by efficient storage.

Also, com•pres•sure  (kəm presh′ər) (for defs. 1, 2).

• Latin compressiōn- (stem of compressiō), equivalent. to compress(us) past participle of comprimere to press together (see com-, press¹) + -iōn- -ion
• Anglo-French)
• Middle English (1350–1400

com•pres′sion•al, adj. 

compression, +n. 

1. Computing reduction of the size of computer data by efficient storage.

Collins Concise English Dictionary © HarperCollins Publishers::

compression / kəmˈprɛʃən/ noun

1. Also called: compressure / kəmˈprɛʃə/ the act of compressing or the condition of being compressed
2. an increase in pressure of the charge in an engine or compressor obtained by reducing its volume