Compressibility , a measure of volume change resulting from pressure
Compression (geology) , a system of forces that tend to decrease the volume of or shorten rocks.
Compression in Zoology and Paleontology refers to where an animal, or part of an animal is shorter or narrower compared with other animals in the same group; eg the body of a lizard may be ''compressed'' (flattened) so it can better fit into crevices under rocks.
Compression Ratio , a number that predicts the performance of any internal-combustion engine