Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĕcūlĭōsus, a, um, adj. [peculium], having a large private property, wealthy (ante- and post-class.): servus, Plaut. Rud. 1, 2, 24; Sid. Ep. 2, 2 fin.; Aug. in Psa. 38.