Perfect passive participle of efficiō (make or work out; accomplish; effect), from ē (out of) (short form of ex) + faciō (do, make).



effectus (feminine effecta, neuter effectum); first/second-declension participle

  1. made out, worked out, completed, finished, accomplished, made, having been worked out
    Synonyms: complētus, absolūtus, perfectus, factus, dēfūnctus
    Antonyms: incohatus, infectus, imperfectus
  2. caused to occur, brought about, having been brought out
  3. produced, yielded, having been produced
  4. (philosophy) shown, proven, deduced, having been proven


First/second-declension adjective.

Number Singular Plural
Case / Gender Masculine Feminine Neuter Masculine Feminine Neuter
Nominative effectus effecta effectum effectī effectae effecta
Genitive effectī effectae effectī effectōrum effectārum effectōrum
Dative effectō effectō effectīs
Accusative effectum effectam effectum effectōs effectās effecta
Ablative effectō effectā effectō effectīs
Vocative effecte effecta effectum effectī effectae effecta


effectus m (genitive effectūs); fourth declension

  1. The act of doing, making or effecting; execution, accomplishment, completion, performance.
  2. An effect, result, outcome, operation, tendency, purpose.
    Synonyms: successus, frūx, frūctus, ēventus, exitus, prōventus


Fourth-declension noun.

Case Singular Plural
Nominative effectus effectūs
Genitive effectūs effectuum
Dative effectuī effectibus
Accusative effectum effectūs
Ablative effectū effectibus
Vocative effectus effectūs



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