Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
saccŭlārĭus, ii, m. [sacculus], one who by juggling tricks, etc., steals money from the pocket; a cut-purse, pick-pocket, swindler, Dig. 47, 11, 7; 18, 1; Ascon. ad Cic. Tog. Cand. p. 90.