A more thorough explanation:

Definition: Praenomen is a Latin term used in Roman law to refer to the first of a person's three names. It was given to distinguish the person from other family members.

Examples: In ancient Rome, a person's praenomen was usually abbreviated to a single letter. For example, Gaius Julius Caesar's praenomen was "G."

Another example is Marcus Tullius Cicero, whose praenomen was "M."

These examples illustrate how the praenomen was used to distinguish individuals within a family. In both cases, the individuals had different praenomens despite sharing the same family name.