(adjective) : in-fĭdēlis, e
* That cannot be relied upon, unfaithful, faithless.
* 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.
* 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.

s. TLL