And there was a crash involved—in Ukrainian perfidy and EU sanctions both.
Grace has been especially severe on the 12-person jury, which she has accused of all manner of perfidy.
1590s, from Middle French perfidie (16c.), from Latin perfidia "faithlessness, falsehood, treachery," from perfidus "faithless," from phrase per fidem decipere "to deceive through trustingness," from per "through" (see per) + fidem (nominative fides) "faith" (see faith).
[C]ombinations of wickedness would overwhelm the world by the advantage which licentious principles afford, did not those who have long practiced perfidy grow faithless to each other. [Samuel Johnson, "Life of Waller"]