fides: auctoritas (the credibility it derives from a sufficient voucher): probabilitas (Cic., 4 Acad., 75 = verisimilitudo): to establish the credibility of anything, credibile aliquid facere; fidem alicui rei facere, addere, or afferre (of things that cause anything to be believed): to prove the credibility of anything to anybody’s satisfaction, alicui aliquid or de aliqua re probare [☞ not credibile aliquid alicui facere, though credibile aliquid facere is correct, Krebs]: the supposed credibility of dreams is done away with, tollitur auctoritas somniorum (Cic.): not to overstep the bounds of credibility in anything, veritatis fidem servare in re: to lose their credibility, fidem amittere (of words, etc.).