Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
praestigĭōsus, a, um, adj. [praestigiae], full of deceitful tricks, delusive (post-class.), Gell. 7, 14, 11: nihil praestigiosum, aut subdolum, Arn. 1, 32.