Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
herctum or erctum, i, n. [HORCTUM et FORCTUM pro bono dicebant, Paul. ex Fest. p. 102 Müll.; perh. kindr. with heres]. In the old jurid. lang., an inheritance, estate, patrimony; only in the connection herctum (erct-) ciere (whence is derived herciscere), to divide an inheritance: qui, quibus verbum herctum cieri oporteat, nesciat, Cic. de Or. 1, 56, 237: herctum non citum, an undivided inheritance, Gell. 1, 9, 12; cf. Don. ap. Serv. Verg. A. 8, 642: herctum citum fit inter consortes, Paul. ex Fest. p. 82 Müll.