What is the definition of misappropriation of funds?

A dictionary definition of misappropriation of funds is the intentional, illegal use of the property or funds of another person for one's own use or other unauthorized purpose, particularly by a public official, a trustee of a trust, an executor or administrator of a dead person's estate, or by any person with a responsibility to care for and protect another's assets (a fiduciary duty).

In short, misappropriation of funds is defined as fraudulent use of funds - money - by a person, persons, entity or entities, other than their legal or rightful owner. The quick synonym is theft.