Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
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.