Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
glossārĭum, ii, n. [glossa], a vocabulary or glossary of antiquated or foreign words that need explanation: vos philosophi meri estis, ut M. Cato ait, mortuaria glossaria; namque colligitis lexidia, res tetras et inanes, etc., Gell. 18, 7, 3.