Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ēmissārĭum, ii, n. [emitto], an outlet: lacūs, a drain, Cic. Fam. 16, 18; Plin. 33, 4, 21, § 75; Suet. Claud. 20, 32: vomicae, Scrib. Comp. 229; cf. collectionis, id. ib. 206.