Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
antĕ-mĕrīdĭānus, a, um, adj., before mid-day or noon: sermo, Cic. de Or. 3, 6: ambulatio, id. ib. 3, 30: litterae, received before mid-day, id. Att. 13, 23.