Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
certĭōro, āvi, ātum, 1, v. a. [certior], = certiorem facere, to inform, apprise, show (only in jurid. Lat., and most freq. used by Ulpian), Gai 2, 190; Dig. 13, 6, 5, § 8; 19, 1, 1 fin.: certioratus, ib. 29, 4, 1, § 4; 43, 29, 3, § 6.