The crossword solution for the term 'Wicked Deed' is SIN, which is a three letter word. SIN is an act that goes against religious or moral laws and is considered to be immoral or wrong. It is often used to refer to actions that are considered to be sinful in Christianity, such as lying, stealing, or murder. Wicked deeds are those that are particularly malicious or evil, and can include acts of violence, fraud, or other immoral behavior.