Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
intergĕrīvus, a, um, adj. [intergeries], that is placed between; subst.: in-tergĕrīvus, i, m. (sc. paries), a partition, party-wall, Plin. 13, 12, 26, § 82; 35, 14, 49, § 173.
Of the walls of wax in a beehive, Plin. 11, 10, 10, § 23.