Illegality (noun)

1. The quality or state of being against the law.
2. An act or circumstance that is against the law.

Origin:

From the late latin word 'illegālitās', meaning 'unlawfulness' which was formed from 'illegālis' meaning 'unlawful'. the word has been in use in english language since 17th century.

Examples:

1. The illegality of the transaction was only discovered after the authorities conducted an investigation.
2. The company was fined for the illegality of its waste disposal practices.
3. The illegality of the action made it difficult for the government to pursue the perpetrators.
4. The court ruled that the contract was void due to its illegality.
5. The illegality of his actions resulted in him being deported from the country.