To clear all definitions or to reclaim resources used by the Wolfram System, you may want to restart the kernel.
Using the Menu...
Quit the kernel
Quit the kernel by choosing Evaluation ▶ Quit Kernel ▶ "kernel name", where “kernel name” is typically “Local”:
Restart the kernel
Any subsequent evaluation will automatically restart the kernel:
Programmatically...
Quit the kernel
Quit the kernel by evaluating Quit:
Restart the kernel
Any subsequent evaluation will automatically restart the kernel:
Using the Menu...
Quit the kernel
Restart the kernel
Any subsequent evaluation will automatically restart the kernel:
Programmatically...
Quit the kernel
Quit the kernel by evaluating Quit:
Restart the kernel
Any subsequent evaluation will automatically restart the kernel: