Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vŏlūtābrum, i, n. [voluto], a wallowing-place for swine. a hog-pool, slough, Verg. G. 3, 411; Salv. adv. Avar. 1, p. 37; Arn. 7, 224; Vulg. 2 Pet. 2. 22.