The best place to find full information on Roman institutions is the Oxford Classical Dictionary (4th edition, 2012). This glossary is designed to help explain terms used in the text.
Adventus The ceremonial entrance of an emperor into a city. The emperor would be welcomed by crowds and speeches, and might hand out gifts to the people. The theme is common on Roman imperial coinages and the ceremony became especially important in the late empire.
ager publicus Land owned by the state, mostly acquired by conquest and leased out to citizens in return for rents (vectigalia).
censor During the Republican period a pair of censors were elected for eighteen months every five years from among the most senior senators. Their duties included reviewing the membership of the senate and equestrian orders, assigning all citizens to their correct political orders and issuing contracts for public works. They also came to exercise moral authority. Under the principate a few emperors took the power of censors or held censorships, and in practice assumed many of their functions.
census Originally the head-count of citizens conducted every year by the censors who also assigned each citizen into an order based on the amount of property he owned. The term later came to be used for periodic assessments of taxliability in the provinces.
centurions The main officers of the legions whose expertise was vital given the aristocratic commanders were often relatively inexperienced. Most centurions commanded units of 80–100 men, and during the Republic were selected from the most experienced soldiers. Under the principate an elaborate hierarchy of ranks and pay developed, and senior centurions were often detached to act as administrators of various kinds.
consul From the early Republic two consuls were elected every year and jointly acted as chief magistrates of the Roman state. Their duties included convening the senate, presiding at major rituals, leading armies and holding elections.
curiales Members of the councils of provincial cities in the Roman empire. The Greek equivalent term was bouleutai. These groups were in effect local equivalents