Open main menu






socius (plural socii)

  1. (historical) Any of the autonomous tribes and city states of the Italian Peninsula in permanent military alliance with the Roman Republic until the Social War of 91–88 BC.
  2. An associate; a fellow of an academy, etc.




From Proto-Indo-European *sokʷ-yo- (companion), from Proto-Indo-European *sekʷ- (to follow)[1]. Compare Faliscan socia (girlfriend, companion).



socius (feminine socia, neuter socium); first/second declension

  1. sharing, joining in, partaking, associated
  2. kindred, related, akin, ally
  3. leagued, allied, united, confederate


First/second declension.

Number Singular Plural
Case / Gender Masculine Feminine Neuter Masculine Feminine Neuter
Nominative socius socia socium sociī sociae socia
Genitive sociī sociae sociī sociōrum sociārum sociōrum
Dative sociō sociō sociīs
Accusative socium sociam socium sociōs sociās socia
Ablative sociō sociā sociō sociīs
Vocative socie socia socium sociī sociae socia

Derived termsEdit

Related termsEdit



socius m (genitive sociī); second declension

  1. partner, sharer, associate
  2. companion, comrade
  3. ally; confederate


Second declension.

Case Singular Plural
Nominative socius sociī
Genitive sociī sociōrum
Dative sociō sociīs
Accusative socium sociōs
Ablative sociō sociīs
Vocative socie sociī


  • socius in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
  • socius in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
  • socius in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition, 1883–1887)
  • socius in Gaffiot, Félix (1934) Dictionnaire Illustré Latin-Français, Hachette
  • Carl Meissner; Henry William Auden (1894) Latin Phrase-Book[1], London: Macmillan and Co.
    • to attach oneself to a person's society: socium se adiungere alicui
    • to admit a person into one's society: aliquem socium admittere
    • a political ally: consiliorum in re publica socius
    • to make some one one's ally: socium aliquem asciscere (B. G. 1. 5)
  • socius in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin
  • Notes: