Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dīreptor, ōris, m. [diripio], a plunderer (very rare; cf.: fur, praedo, raptor), Cic. Phil. 3, 11, 27; id. Cat. 2, 9 fin.; Tac. H. 3, 33.