> "Probable cause of a crime" means what?

The usual full expression is something like “probable cause to believe that the person to be arrested has committed a particular crime”.

> "Probable cause" can be used to justify a search.

“Probable cause” is a constitutional requirement for search warrants, arrest warrants, warrantless arrests, and warrantless searches; for searches, the probable cause is that the search conducted will uncover evidence of a crime, which is different than the probable cause for arrest.

> You would need to actually be suspected of a crime.

Well, no, there needs to be probable cause to believe you've committed a crime. Actual suspicion is a much lower standard.

> If the cops don't find drugs, what crime are you guilty of?

There are...like thousands of other crimes, and millions of possible configurations of things that are not drugs that could support probable cause to believe you've committed one of them. Spray paint cans consistent with a recent spate of vandalism (graffiti) in the area is one I’ve personally seen used, beyond things that are inherently actual or apparent contraband, and the “actual or apparent contraband” category extends to more than just drugs.

In america you can be hauled in and convicted of nothing more than "resisting arrest", with no other prior crime or suspected crime. If a cop tries to arrest you and you do ANYTHING other than comply, that's a crime

This is false. Probably cause just means they can search your car. Not that you are going to jail.

Probable cause is the bar for arrest. If they have probable cause, you're getting arrested.

Yes, but without evidence you aren’t going to jail, and if you do you can sue for wrongful arrest.

> Yes, but without evidence you aren’t going to jail, and if you do you can sue for wrongful arrest.

You can sue anyone, anytime, for anything, but even if charges aren't filed or a court dismisses them at the preliminary hearing stage for lack of sufficient evidence, wrongful arrest suits against police are very difficult.

Do you mean "suspected of committing a crime"? "Probable cause" relates to searching or entering private property.

> Do you mean "suspected of committing a crime"?

No, mere suspicion is not sufficient for arrest.

> "Probable cause" relates to searching or entering private property.

It also relates to arrest. The Fourth Amendment provision applying the standard explicitly applies to searches and seizures of persons, houses, and effects. Arrest is seizure of one’s person.

Yes, but probably cause isn’t some binary.

A drug dog’s indications provide probable cause for searching your car, but are not enough to arrest you.

No.

> Probably cause just means they can search your car. Not that you are going to jail.

Probable cause (of slightly different things; the threshold is the same but the subject is different) is the bar for both search and arrest.