Hastings' Dictionary of the Bible (1898)
PUB'LICAN, an inferior collector of the Roman tribute. Matt 18:17. The principal farmers of this revenue were men of great credit and influence, but the under-farmers, or publicans, were remarkable for their rapacity and extortion, and were accounted as oppressive thieves and pickpockets. Hence it is even said that the Jews would not allow them to enter the temple or the synagogues, to partake of the public prayers or offices of judicature, or to give testimony in a court of justice. There were many publicans in Judaea in the time of our Saviour.
Zacchaeus was probably one of the principal receivers, since he is called "chief among the publicans," Luke 19:2; but Matthew was only an inferior publican. Luke 5:27. The Jews reproached Jesus with being a "friend of publicans and sinners " and eating with them. Luke 7:34.