What does the phrase bread and circuses mean?

"Bread and circuses" refers to the pacification of a populace by food and entertainment, which is related to the term "fat and happy".

As coined by the Roman poet Juvenal (c. 100-200 AD) in his Satires, panem et circenses was an apparent policy in the Roman Empire. The rulers believed that if the people were entertained and their bellies full, they would not get restless or try to overthrow the government. So they tried to make sure that there was always entertainment, notably in the Colosseum, and that there was always bread available to be purchased. In this way, the Roman masses were distracted from the problems of the Empire.