Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prae-densus, a, um, adj., very thick, very dense (post-Aug.): farrago, Plin. 18, 16, 41, § 142: grana, id. 18, 7, 10, § 53: terra, id. 18, 18, 48, § 171.