Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ērĭnācĕus (herin-), i, m. [er; cf. ericius], a hedgehog, Plin. 8, 37, 56, § 133; 10, 63, 83, § 174 al. (Sillig; dub.
Jan. irenaceus).