Lewis Short
conjūrātĭo (noun F) : conjuro
* A swearing together.
* Prop.
* In gen.: conjuratio fit in tumultu, i. e. Italico bello et Gallico quando vicinum urbis periculum singulos jurare non patitur,Serv. ad Verg. A. 7, 615; cf. id. ib. 2, 157; 8, 1 and 5.—Hence, transf., a union or alliance: quae haec est conjuratio! utin omnes mulieres eadem aeque studeant nolintque omnia,Ter. Hec. 2, 1, 1: urbana,Plin. Pan. 70 fin.
* Meton. (abstr. pro concr.), the confederacy, the band of conspirators themselves: perditorum hominum,Cic. Cat. 1, 6, 13.
* In a bad sense, a conspiracy, plot (in good prose; most freq. in the histt.),Cic. Cat. 2, 4, 6; Caes. B. G. 1, 2; Sall. C. 17, 1 et saep.: si omnia facienda sunt, quae amici velint: non amicitiae tales, sed conjurationes putandae sunt,Cic. Off. 3, 10, 44: convicti adversum se conjurationis,Eutr. 7, 21: conjuratio nefanda in omne facinus ac libidinem,Liv. 39, 38, 3.
Charlton T. Lewis, Charles Short, A Latin Dictionary