Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
dē-rēpo, psi, 3, v. n., to crawl down, sneak down (very rare): derepit ad cubile setosae suis, Phaedr. 2, 4, 12: ad hominum fana, Varr. ap. Non. 544, 29; Ap. M. 4, p. 145.