Compressor/kəmˈpresər/ Definition 1 of 3Pro Tip 1/3Pressure Application Compressor as a tool that applies force to condense materials or elements. The workshop uses a compressor to compact metal scraps. Pro Tip 2/3Space Efficiency Compressor often implies making something more space-efficient through pressure. A trash compressor can greatly reduce the volume of waste. Pro Tip 3/3Mechanical Tool A compressor is usually a large, noisy piece of machinery, not a simple hand tool. The loud compressor startled me as it turned on.