Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prae-gĕlĭdus, a, um, adj., very cold: in locis praegelidis, Liv. 21, 54: frigora, Col. 4, 8: hiems, Plin. 9, 16, 24, § 57: rivi, Sil. 4, 226.