Sin (noun)

1. An action or thought that is against religious or moral law.
2. A failure to fulfill a religious or moral duty.
3. A wrongdoing or evil.
4. A misdeed or transgression.
5. A stain on one's character or reputation.

Origin:

Old english synn, of germanic origin; related to dutch zonde and german sünde.

Examples:

1. Stealing is considered a sin in many cultures.
2. He felt guilty for his sins and sought forgiveness.
3. Her lies were a sin against the truth.
4. The priest absolved him of his sins.
5. Her past misdeeds were seen as a black sin on her record.