Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
in-cerno, ĕre, v. a., to sift upon a thing, to cover or bestrew with sifting; to sift, scatter with a sieve: terram cribro, Cato, R. R. 48, 2; Col. 5, 6, 6: super fricaturam incernatur marmor, Vitr. 7, 1: incretum ( = per incerniculum sive cribrum inspersum), sifted in, Hor. S. 2, 4, 75 Orell. (but in Plin. 37, 6, 23, § 87, the correct read. is redimitum; v. Sillig. ad h. l.).