Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† presbytĕrĭum, ĭi, n., = πρεσβυτέριον, a presbytery, assembly of elders, August. ap. Hier. Ep. 116, 33 fin.; Vulg. 1 Tim. 4, 14.