Soften (verb)

1. To make or become less hard, tough, or rigid; become or make more pliant.
2. To make or become less severe, harsh, or strict; become or make milder.

Origin:

From old english sōfian, from proto-germanic *sōfijaną, from proto-indo-european *seh₂- ("smoot.h")

Examples:

1. He softened the blow by saying it wasn't my fault.
2. The metal will soften when heated.
3. The rules were softened to make them more palatable.
4. She softened her tone so as not to alarm the children.
5. The sun has softened the snow.