Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dēpŏpŭlātĭo, ōnis, f. [depopulor], a laying waste, marauding, pillaging (several times in Cic.; elsewh. rare), Cic. Pis. 17, 40; id. Verr. 1, 4, 12; id. Rep. 2, 14; Liv. 43, 23: Thracum, Cic. Font. 22, 44: Tiberini fluminis igniumque, ravages, Aug. Civ. Dei, 3, 31; Vulg. Mic. 2, 4. In plur., Cic. Phil. 5, 9, 25.