Etymology 1Edit

From Proto-Italic *feiðos, from Proto-Indo-European *bʰeydʰ-os, from *bʰeydʰ-. Same root as fīdō, fidēs, fīdus, and Proto-Germanic *bīdaną. Perhaps a corruption from an o-stem.


foedus n (genitive foederis); third declension

  1. treaty, agreement, contract
    Synonym: conventum
  2. league
  3. pact, compact
  4. (biblical) covenant

Third-declension noun (neuter, imparisyllabic non-i-stem).

Case Singular Plural
Nominative foedus foedera
Genitive foederis foederum
Dative foederī foederibus
Accusative foedus foedera
Ablative foedere foederibus
Vocative foedus foedera
Derived termsEdit

Etymology 2Edit

From Proto-Indo-European *bʰeyh₂- (to frighten; be afraid).


foedus (feminine foeda, neuter foedum, comparative foedior, superlative foedissimus, adverb foedē); first/second-declension adjective

  1. (physically) filthy, foul, disgusting, loathsome, ugly, unseemly, detestable, abominable, horrible
    Synonym: nefandus
  2. (mentally) disgraceful, vile, obscene, base, dishonorable, shameful, infamous, foul

First/second-declension adjective.

Number Singular Plural
Case / Gender Masculine Feminine Neuter Masculine Feminine Neuter
Nominative foedus foeda foedum foedī foedae foeda
Genitive foedī foedae foedī foedōrum foedārum foedōrum
Dative foedō foedō foedīs
Accusative foedum foedam foedum foedōs foedās foeda
Ablative foedō foedā foedō foedīs
Vocative foede foeda foedum foedī foedae foeda
Derived termsEdit


  • foedus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
  • foedus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
  • foedus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition with additions by D. P. Carpenterius, Adelungius and others, edited by Léopold Favre, 1883–1887)
  • foedus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette
  • Carl Meißner; Henry William Auden (1894) Latin Phrase-Book[1], London: Macmillan and Co.
    • to conclude a treaty, an alliance: foedus facere (cum aliquo), icere, ferire
    • to violate a treaty, terms of alliance: foedus frangere, rumpere, violare
    • (ambiguous) according to treaty: ex pacto, ex foedere
  • foedus”, in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
  • foedus”, in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin