Corruption is dishonest action that destroys people's trust. News of corruption at your bank might make you close your account and invest your money somewhere else.
The noun corruption comes from Latin — com, meaning "with, together," and rumpere, meaning "to break." Engaging in corruption can "break" or destroy someone's trustworthiness and good reputation with others. For example, news of corruption in the mayor's office might cause shock and lead to the election of a new mayor. When you corrupt something that is pure or honest, you take away those qualities. That's why "corruption of minors" is a serious offense in our legal system.