Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
īrēnācĕus, i, m., a hedgehog (al. erinaceus, herinaceus), Plin. 8, 37, 56, § 133; 10, 63, 83, § 174; 30, 8, 21, § 65; 8, 35, 53, § 125.