renice
Explanation
The renice command changes the nice level of a running process. The nice level is a value that affects the scheduling priority of a process. A lower nice level means a higher priority and a higher nice level means a lower priority. The renice command requires the process ID (PID) of the target process and the new nice level as arguments. For example, renice -n 10 1234 will change the nice level of the process with PID 1234 to 10.
References: LPI Exam 101 Detailed Objectives, Topic 103: GNU and Unix Commands, Weight: 25, Objective 103.3: Perform basic file management, renice command