What does warrant overpaid benefits employment security mean?

I don't quite understand what you are asking. There are many types of judgments, money judgments, criminal judgments, etc. A warrant normally means that there is a warrant for someone's arrest. If that person presents himself to court, he may (or may not) avoid jail and typically a warrant doesn't have much to do with a money judgment, unless someone failed to appear for court. Need more information.

Warrant means many things. You may warrant (deserve) a raise. A warrant may be issued for your arrest. L&I issues warrants, which are checks for travel, for example. In Washington, the Employment Security Department is the state agency that pays unemployment benefits.
Yes, if a civil court enters a judgment, it is enforceable, even if the defendant does not believe they owed the money. You cannot be jailed for failing to pay a civil judgment, in most cases.
I suggest that you schedule a free half-hour consultation with an attorney and bring whatever paperwork you have, so the attorney can help you understand what those words mean in context.
Good luck to you.

Often the Employment Security Department will issue a warrant for overpaid benefits. It is essentially a civil judgment allowing the department to take further collection action against you, including garnishment and liens, if necessary. I suggest consulting with an employment attorney in your area.