The verb form of soften means to make something or someone less harsh, severe, intense, or difficult. It can also mean to become softer in nature or character. When used as a transitive verb, it means to cause (something) to become more gentle or tender by removing its roughness or severity.
For example: "The warm water softened the cloth." This sentence implies that the heat from the water made the fabric more pliable and less stiff. In another context, one might say, "Her kind words softened my anger towards her," meaning that she had apologized in a way that made him feel less upset or resentful.
In summary, to soften means to make something or someone easier to approach, handle, or experience by reducing its harshness or severity.