Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
praestigĭātor, ōris, m. [praestigiae], a juggler, cheat, impostor, deceiver (anteclass. and post-Aug.): praestigiator hic quidem Poenus probu’ est, Plaut. Poen. 5, 3, 6; id. Aul. 4, 4, 3; Sen. Ep. 45, 8: pervicaci praestigiator actu, the devil, Prud. Cath. 6, 141 (with i long).