Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Andriscus, i, m., = Ἀνδρίσκος, a slave who claimed to be the son of the Macedonian king Perseus and occasioned the third Macedonian war, Liv. Epit. 49; Vell. 1, 11; Flor. 2, 14.