Lewis & Short

ărăbarches (this is the proper form, not ălăbarches; cf. Haeckermann in Jahn’s Neue Jahrbb. 1849, 15, supplem., pp. 450-566; very likely some said alabarches and alabarchia, because of the foll. r, to avoid two rs), ae, m., = ἀραβάρχης, an officer of customs in Egypt, Juv. 1, 130 Jahn, Hermann.
Sarcastically of Pompey, because he boasted that he had augmented the taxes so much: velim ex Theophane expiscere, quonam in me animo sit Arabarches, Cic. Att. 2, 17, 3.