Legalization/ˌliːɡələˈzeɪʃn/ Definition 1 of 3Pro Tip 1/3Societal Change Indicates a shift in society's view on a previously illegal act. The legalization of same-sex marriage marked a societal advance. Pro Tip 2/3Government Role Emphasizes a government's action in changing the law. Legalization of certain substances requires new regulations. Pro Tip 3/3Often Controversial Reflects that such changes can be divisive or topic of debate. The debate on the legalization of drugs continues.