perfidy

Definition

A state or act of violating faith or allegiance; violation of a promise or vow, or of trust.

Etymology

From Middle French perfidie, from Latin perfidia from perfidus (“faithless, treacherous, false”), from fides (“faith”); related to, for example, English fidelity.

Example Sentences

• "Stratagems must be carefully distinguished strategy from perfidy, since the former are allowed, whereas the latter is prohibited."
• "Abuse of a protective emblem amounts to perfidy and constitutes a war crime under the customary law of armed conflict."
• "Ruses of war are legitimate so long as they do not involve treachery or perfidy on the part of the belligerent resorting to them."