Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prae-ferrātus, a, um, adj., tipped or shod with iron: modius, Cato, R. R. 11: pilum, pointed with iron, Plin. 18, 10, 23, § 97.
Transf.: praeferratus apud molas tribunus, i. e. chained, fettered, Plaut. Pers. 1, 1, 22.