de·crimi·nal·ize decriminalizes decriminalizing decriminalized in BRIT, also use decriminalise When a criminal offence is decriminalized, the law changes so that it is no longer a criminal offence. the question of whether prostitution should be decriminalized. + decriminalization de·crimi·nali·za·tion the decriminalisation of homosexuality in the Isle of Man. to state officially that something is not illegal any more