Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prae-sicco, āvi, 1, v. a., to dry beforehand (post-class.), Cael. Aur. Tard. 2, 14, 217; 4, 3, 53.
Hence, prae-siccātus, a, um, dried beforehand (post-class.): succus sole praesiccatus, App. Herb. 124.