perfidus

Latin

Etymology

From per (“through, along”) + fidēs (“faith; trust”) + -us (“adjectival suffix”).

Pronunciation

• (Classical Latin) IPA^(key): /ˈper.fi.dus/, [ˈpɛrfɪd̪ʊs̠]
• (modern Italianate Ecclesiastical) IPA^(key): /ˈper.fi.dus/, [ˈpɛrfid̪us]

Adjective

perfidus (feminine perfida, neuter perfidum); first/second-declension adjective

1. That breaks his promise; faithless, false, dishonest, treacherous, perfidious, deceitful.
2. (by extension) Treacherous, unsafe, dangerous.

   Synonym: īnfīdus

Declension

First/second-declension adjective.

	singular				plural
	masculine	feminine	neuter		masculine	feminine	neuter
nominative	perfidus	perfida	perfidum		perfidī	perfidae	perfida
genitive	perfidī	perfidae	perfidī		perfidōrum	perfidārum	perfidōrum
dative	perfidō	perfidae	perfidō		perfidīs
accusative	perfidum	perfidam	perfidum		perfidōs	perfidās	perfida
ablative	perfidō	perfidā	perfidō		perfidīs
vocative	perfide	perfida	perfidum		perfidī	perfidae	perfida

Antonyms

• (faithless): castus, honestus, pudīcus

Derived terms

• perfidē
• perfidia

Related terms

• perfidiōsē
• perfidiōsus

Descendants

• English: perfidious
• French: perfide
  • German: perfide
• Italian: perfido
• Portuguese: pérfido
• Spanish: pérfido

References

• “perfidus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• “perfidus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• perfidus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette.