Use 'illegality' when discussing issues related to law or actions that break the law. The contract was void due to the illegality of its terms.
Pro Tip 2/3
Negative Connotation
'Illegality' carries a negative meaning, often suggesting wrongdoing or criminal behavior. The company faced scrutiny for the illegality of its waste disposal methods.
Pro Tip 3/3
Formal Register
'Illegality' is formal and mainly used in legal, academic, or professional settings. The proceedings focused on the illegality of the mayor's actions.