A more thorough explanation:

Definition: A publican is a person who has a license to run a public house where people can drink alcohol on or off the premises.

For example, if you go to a bar or a pub, the person who serves you drinks is a publican. They are responsible for making sure that the customers are of legal drinking age and that they don't drink too much.

In ancient times, a publican was also a tax collector. They would collect taxes from the people on behalf of the government. This is where the word "publican" comes from.

Overall, a publican is someone who is authorized to sell alcohol and make sure that people drink responsibly.