The reason you get those google results is because your understanding is not consistent with how other people use the words. Your suggested usage is reasonable

The reason you get those google results is because your understanding is not consistent with how other people use the words. Your suggested usage is reasonable, but it's not the usage that is common, and I suggest that you change your understanding. Legalization has always meant "making it legal", which in most societies means "removing laws that make it illegal" (though it might mean something different in North Korea, if you see what I mean). Decriminalization is a wishy-washier idea, that includes lightening or removing criminal penalties, while potentially keeping other penalities. For example, changing indictable offenses to non-indictable offenses (in the U.S. that'd be roughly equivalent to changing felonies to misdemeanours). Prostitution should be legalized, not merely have the penalties lightened. And that alone is not sufficient; legal regimes that legalize the actual act of sex-for-money, but still force most prostitutes to hide from the cops (I'm looking at Canadian law, here) are still inadequate, because such regimes still victimize sex workers (consensual or otherwise). It's simply a human rights issue. I also think it's clear that some degree of regulation is desirable, but I think that reasonable people can disagree on this.