Cap of maintenance, also known as capitation, is a phrase used to describe a fee paid by families and individuals for the upkeep of the royal family or nobility. There are a number of different synonyms that can be used to refer to this concept. One option is "poll tax," which is a tax that is levied on each individual within a society regardless of their wealth or income. Another synonym is "diem," which refers to a daily fee that is charged by the government for the upkeep of its officials. Other potential synonyms for the cap of maintenance include "tribute," "ransom," and "levy," among others.