LATIN DICTIONARYLexicon Latīnum
adjectivefirst/second-declension adjective

perfidiōsus

perfidiōsus (feminine perfidiōsa, neuter perfidiōsum, comparative perfidiōsior)
Classical[pɛr.fɪ.diˈoː.sʊs]Ecclesiastical[per.fi.diˈɔː.s̬us]
perfidiōse sg. voc. m.

Meaning

  1. adjectivetreacherous, perfidious

Choosing the right word Döderlein's Latin Synonyms

Fidus · Fidelis · Infidus · Infidelis · Perfidus · Perfidiosus

1. Fidus denotes a natural quality, like trustworthy, with relative praise; whereas fidelis denotes a moral characteristic, as faithful, with absolute praise. Liv. xxii. 22. Eo vinculo Hispaniam vir unus solerti magis quam fideli consilio exsolvit. Abellex erat Sagunti, nobilis Hispanus, fidus ante Pœnis. 2. Infidus means unworthy of trust; infidelis, unfaithful; perfidus, treacherous, in particular actions; perfidiosus, full of treachery, with reference to the whole character. (v. 255.)

Declension

singular
formmasculinefeminineneuter
nominativeperfidiōsusperfidiōsaperfidiōsum
genitiveperfidiōsīperfidiōsaeperfidiōsī
dativeperfidiōsōperfidiōsaeperfidiōsō
accusativeperfidiōsumperfidiōsamperfidiōsum
ablativeperfidiōsōperfidiōsāperfidiōsō
vocativeperfidiōseperfidiōsaperfidiōsum
plural
formmasculinefeminineneuter
nominativeperfidiōsīperfidiōsaeperfidiōsa
genitiveperfidiōsōrumperfidiōsārumperfidiōsōrum
dativeperfidiōsīsperfidiōsīsperfidiōsīs
accusativeperfidiōsōsperfidiōsāsperfidiōsa
ablativeperfidiōsīsperfidiōsīsperfidiōsīs
vocativeperfidiōsīperfidiōsaeperfidiōsa

perfĭdĭōsus, a, um, adj. perfidia,
I. faithless, dishonest, treacherous, false, perfidious (class.).
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.—
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.

Origins

From perfidia (“perfidy”) + -ōsus (“-ous”), from perfidus (“faithless”) + -ia (“-ness”), from per (“through”) + fidēs (“trust”), from Proto-Indo-European *per + Proto-Italic *feiðos from root *bʰeydʰ-.

Descendants
  • Englishperfidious

In English words that came into English from perfidiōsus

  • perfidiousperfidiōsus

Quick answers

What does perfidiōsus mean in Latin?
perfidiōsus, a adjective, means “treacherous, perfidious”.
How do you pronounce perfidiōsus?
In classical Latin, [pɛr.fɪ.diˈoː.sʊs]; in ecclesiastical (church) Latin, [per.fi.diˈɔː.s̬us].