Lewis & Short

interventus, ūs, m. [intervenio], a coming up, appearance, coming between, intervention.

  1. I. Lit.
    1. A. Of persons: interventus alicujus, Cic. Part. 8, 30: Caleni et Calvenae, id. Att. 16, 11, 1: Pomptini, id. Cat. 3, 3, 6: hominum, Liv. 26, 19: Alexandri, Just. 11, 1, 7.
    2. B. Of inanim. and abstr. things, a coming between, intervention, occurrence: id proelium diremit nox interventu suo, Plaut. Am. 1, 1, 99: amnis alicujus interventu arceri, Plin. 29, 3, 12, § 52: solem interventu lunae occultari, id. 2, 10, 7, § 47: noctis, Caes. B. G. 3, 15: malorum, Cic. N. D. 1, 40: interventu feriarum impediri, Dig. 4, 6, 26, § 7.
  2. II. Transf., interposition, mediation, assistance: principis, Trajan. ad Plin. Ep. 10, 68: judicis, Dig. 33, 1, 7: sponsorum, i. e. bail, Suet. Caes. 18.
    Esp., in a suit at law, the substitution of a new plaintiff or defendant, Gai. Inst. 3, 176.