Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
per-maxĭmus, a, um, adj., very great indeed, extremely great: solitudo, Porc. Latro Decl. ap. Cat. 21.
Adv.: permaxĭ-mē, very greatly, particularly, Cato, R. R. 38, 4 dub.; Ps.-Aug. ad Fratr. Erem. Serm. 69 (Schneid. maxime).