Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĕr-indignē, adv., v. perindignus fin.
pĕr-indignus, a, um, adj., very unworthy, very unbecoming, Sid. Ep. 4, 4.
Adv.: pĕrindignē, very indignantly (post-Aug.): tulit perindigne actum a senatu, ut, etc., Suet. Tib. 50.