Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ercisco and erctum, v. hercisco.
hercisco or ercisco, ĕre, v. a. [contr. from herctum or erctum and cisco, as a v. inch. from cieo; cf. herctum], in the old jurid. lang., to proceed to the division of an inheritance, to divide an inheritance.