Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dēpŏpŭlātor, ōris, m. [depopulor], one who lays waste, a marauder, spoiler, pillager: fori, Cic. Dom. 5, 13; Caecil. ap. Non. 118, 33 (v. 191 Rib.); Vulg. Isa. 21, 2.