Lewis & Short

Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.

perfĭdĭōsē, adv., v. perfidiosus fin.

perfĭdĭōsus, a, um, adj. [perfidia], faithless, dishonest, treacherous, false, perfidious (class.).

  1. I. Of persons: fallax, perfidiosus, Cic. Pis. 27, 66: perfidiosus et subdolus animo, Tac. A. 16, 32.
    Sup.: omnium perfidiosissimus, Cic. N. D. 3, 32, 80.
  2. II. Of inanim. and abstr. things: amor, Plaut. Cist. 1, 1, 73: nihil perfidiosum et insidiosum et fallax in amicitiā, Cic. Fam. 3, 10, 7; id. Rosc. Com. 6, 16.
    Adv.: per-fĭdĭōsē, faithlessly, dishonestly, treacherously, perfidiously (rare but class.): hercle istam rem judicasti perfidiose, Plaut. Curc. 5, 3, 41: multa perfidiose facta, Cic. Rosc. Am. 40, 118: perfidiose, crudeliter factum, Auct. Her. 1, 5, 8.
    Comp.: perfidiosius rebellantes, Suet. Aug. 21.