Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
crābro, ōnis, m., a hornet: Vespa crabro, Linn.; Plin. 11, 21, 24, § 71 sq.; Ov. M. 11, 335; Verg. G. 4, 245 al.
Prov.: irritare crabrones, to stir up a hornet’s nest, Plaut. Am. 2, 2, 84.