Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
lustror, āri, v. dep. n. [1. lustrum], to frequent places of ill-repute: circum oppida, Lucil. Sat. 30, 68: lustrantur, comedunt quod habent, Plaut. Ps. 4, 7, 6: ubi fuisti, ubi lustratus, id. Cas. 2, 3, 29.