- noun an extra specialised processor, e.g. an array or numerical processor, that can work with a main CPU to increase execution speed
- Also spelled co-processor. In a computer, a secondary CPU which performs specialized functions that assist the main CPU. For instance, even though a CPU can perform floating-point calculations, a math coprocessor can do so better, and at the same time free the main CPU to address other tasks. Another type of coprocessor is a graphics coprocessor. A CPU may have a coprocessor built into it.