There are tons of antonyms for credible out there, but really good ones include deceptive, dishonest, undependable, unreasonable, etc...
Hope this helped!!!!!
Depends, but usually it is an aristocrat where basically one ruler/leader rules the entire nation. For example, the many dynasties in China which was lead by an emperor. Then there is constitutional monarchy where there is a monarch present, but they have no real power and power lies with parliament (Congressional law making body). Examples of constitutional monarchy includes the United Kingdom, Japan, Spain, and Thailand (though I believe the monarch still have a lot of say and power).
