I.that cannot be relied upon, unfaithful, faithless.
I. In gen. (rare but class.): “si hoc sibi sument, nullam esse fidem, quae infideli data sit,” Cic. Off. 3, 29, 106: “Bellovaci, qui ante erant per se infideles,” Caes. B. G. 7, 59: “non infideles arbitrae Nox et Diana,” Hor. Epod. 5, 50: “obsecro, infidelior mihi ne fuas, quam ego sum tibi,” Plaut. Capt. 2, 3, 83: “ut ex infidelissimis (sociis) firmissimos redderem,” Cic. Fam. 15, 4, 14: “silex ad structuram infidelis,” Plin. 36, 22, 49, § 169: “infidelis recti magister est metus,” Plin. Pan. 45.—
II. In partic., in eccl. Lat., unbelieving, infidel: “Christiani,” Salv. de Gub. 5 init.—Adv.: in-fĭdēlĭter , faithlessly, perfidiously: “nec me minus putarem reprehendendum, si inutiliter aliquid senatui suaserim quam si infideliter,” Cic. Brut. 2, 1, 2; Vulg. Isa. 21, 2. —Sup.: infidelissime, Salv. contra Avar. 3.