What is Lex Claudia?

Legal Definition
Lex Claudia (Classical Latin: [ˈlɛks ˈklawdɪa]) was a law established in ancient Rome in 218 BC. The law was written by Quintus Claudius, then Tribune of the Plebs, stating that no senator or senator’s son could own a sea-going ship with a capacity of more than 300 amphorae (an amphorae is roughly the equivalent of six gallons, making the total ship capacity equal to about seven tons ). Though Q. Claudius was the only proponent of the law, the law was pushed through the Senate because of the support of Gaius Flaminius Nepos, consul at the time. The law prevented senatorial families from profiting from overseas trade. In Rome, senators were legally prohibited from participating in trade. Gaining wealth through mercantile activities was considered a lower-class activity and those of higher status based their wealth on landholdings, government positions, and profits from war. Regardless of this, senators had found ways of circumventing these laws. Lex Claudia sought to curtail these mercantile profits by senatorial families. As it was introduced right before the beginning of the second Punic War, it may also have been an attempt by the plebeians and common people of Rome to prevent senators from benefiting financially from overseas wars. The law can be viewed as an attempt to ensure that the senators who made decisions regarding wars did so with the good of the Roman Republic in mind, not their own personal financial interests. This view allows us to understand why Flaminius, though all the senators opposed him, pushed the law through the Senate in order to ensure allegiance to the Roman Republic and strengthen military decision-making. Senators seem to have opposed the law simply because it interfered with their freedom. As a result of the law, senatorial families increased investments in commercial companies and land holding in the Italian peninsula. The law represents one of the first instances of an attempt to separate the governing class from the commercial class in the Roman Republic.

The law forced Roman senators into large-scale farming and pushed the equites into the business of international shipping. The enormous farms of Roman senators are said to have created conditions leading to the rise of the Gracchi in 133 BC, during the late Roman Republic. This law appears to have become obsolete by the time of Cicero.
-- Wikipedia
Legal Definition
A law which abolished the ancient guardianship of adult women by their male agnate relations. See Mackeld. Rom. Law, § 615.
-- Black's Law Dictionary