[per-FID-ee-us]
Definition
- (adjective) Someone who is deceitful and untrustworthy, particularly someone who betrays trust or breaks their promises. It refers to behavior that is treacherous, disloyal, or faithless.
Example
The perfidious business partner secretly sold company secrets to competitors while pretending to be dedicated to the firm’s success.
Fun Fact
“Perfidious” comes from the Latin “perfidiosus,” derived from “perfidia” meaning “faithlessness” or “treachery.” The word breaks down into “per” (meaning “through” or “away from”) and “fides” (meaning “faith” or “trust”). This same Latin root “fides” gives us other words like “fidelity,” “confident,” and “fiduciary.” The term gained particular historical significance in the phrase “Perfidious Albion,” a pejorative term used by France and other European nations from the 13th century onward to describe what they saw as England’s tendency to be diplomatically unreliable or treacherous. During the medieval period, being perfidious was considered one of the most serious character flaws a noble could possess, as it violated the feudal code of honor and loyalty. Today, while less commonly used, it remains one of the strongest words in English for describing betrayal and untrustworthiness.
