From BiblePortal Wikipedia

Hawker's Poor Man's Concordance And Dictionary [1]

I stop to note a circumstance in the history of the conversion of Zaccheus, which deserves attention. The Lord Jesus observed, when speaking of the salvation that was then to come to his house, "for so much as he also is a son of Abraham." ( Luke 19:1-10) Now if Zaccheus was, as is Generally supposed, a Gentile by birth, this sonship in Abraham must have been as Paul speaks of it, spiritually. "If ye be Christ, then are ye Abraham's seed, and heirs according to the promise." ( Galatians 3:29) I do not speak positively upon the subject; but the office of a Publican or Taxgatherer among the Romans was so invidious an employment that few of the Jews would engage in it. So that it is probable, Zaccheus might have been a gentile. And hence, by the way, a sweet testimony to that blessed truth, that Christ was given both for a light to lighten the Gentiles, and to be the glory of his people Israel. ( Isaiah 49:6) ( Luke 2:32) If Zaccheus derived his name, as is supposed, from Zacac, of the Syriac, meaning just, or justified; the name was truly applicable to the person, justified freely as he was in the salvation of Christ.

American Tract Society Bible Dictionary [2]

Just, from the Hebrew Zaccai,  Nehemiah 7:14 , a worthy tax-gatherer at Jericho, who in order to see Christ took a position in a sycamore-tree, by which He was about to pass. The Savior drawing near and knowing his heart, called him to come down, and proposed to become his guest. As he held office under the Romans, he was called "a sinner" by the Jews,  Luke 19:1-10 . He showed sincere penitence and faith in the Savior, who in turn promised him salvation as a child of Abraham by faith,  Galatians 3:7 , as he also seems to have been by birth.

The "house of Zaccheus" now shown on the plain of Jericho is probably the remnant of a fort built in the tenth century, or even more recently.

Watson's Biblical & Theological Dictionary [3]

chief of the publicans; that is, farmer general of the revenues,  Luke 19:1 , &c. This is all that is known concerning this person. See Publicans and See Sycamore .

Holman Bible Dictionary [4]

 Luke 19:2-9

Kitto's Popular Cyclopedia of Biblial Literature [5]

Zacche´us, a superintendent of taxes at Jericho. Having heard of the Redeemer, he felt a great desire to see him as he drew near that place; for which purpose he climbed up into a sycamore-tree, because he was little of stature. Jesus, pleased with this manifestation of his eagerness, and knowing that it proceeded from a heart not far from the kingdom of God, saw fit to honor Zaccheus by becoming his guest. This offended the self-righteous Jews, who objected that 'he was gone to be a guest with a man that is a sinner.' This offensive imputation was met by Zaccheus in the spirit of the Mosaic conception of goodness—'The half of my goods I give to the poor; and if I have taken anything from any man by false accusation, I restore him fourfold.' He that knew the heart of man knew not only the truth of this statement, but that the good works of Zaccheus emanated from right motives, and therefore terminated the conversation with the words, 'This day is salvation come to this house, forsomuch as he also is a son of Abraham'—a declaration which, whether Zaccheus was by birth a Jew or not, signifies that he had the same principle of faith which was imputed to Abraham, the father of the faithful, for righteousness (, sq.).

Tradition represents Zaccheus as the first Christian bishop of Cesarea.