Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† 1. zoster, ēris, m., = ζωστήρ (a girdle).
2. Zoster, ēris, m., a promontory, town, and harbor of Attica; the promontory is now called C. Lombarda, Cic. Att. 5, 12 init.