Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pŏpŭlābundus, a, um, adj. [populor], laying waste, ravaging (rare): agros populabundus, Sisenn. ap. Non. 471, 23; cf.Gell. 11, 15, 7: in fines Romanos excurrerunt populabundi, Liv. 1, 15, 1: vagari populandum, id. 2, 60, 2: consul per agrum populabundus ierat, id. 3, 3, 10.