Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dē-pĕtīgo, ĭnis, f. [petigo], a leprosy, scab, spread over the whole body (v. de, no. II. 2. c.), Cato R. R. 157 fin.; cf.: scabies deque petigo, Lucil. ap. Non. 160, 18.