1. the act of mitigating, or lessening the force or intensity of something unpleasant, as wrath, pain, grief, or extreme circumstances:
Social support is the most important factor in the mitigation of stress among adolescents.
2. the act of making a condition or consequence less severe:
the mitigation of a punishment.
3. the process of becoming milder, gentler, or less severe.
4. a mitigating circumstance, event, or consequence.