Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĕr-incommŏdus, a, um, adj., very inconvenient, very troublesome or annoying: alicui, Liv. 37, 41, 3.
Adv.: pĕrin-commŏdē, very inconveniently, very unfortunately: accidit perincommode, quod, etc., Cic. Att. 1, 17, 2.