Welcome to “Off the Clock,” a little something that lands somewhere between Timeless & Timely.
I send out this fun look at language and words every other Saturday as bonus content. If someone sent this to you, please consider subscribing.
As someone who is interminably interested in words, I’m always looking for ways to expand my vocabulary.
The trouble with writing a newsletter that asks people to think and to learn is that there is a temptation to err on the side of erudition and showcase my dialectical prowess.
While such a mellifluous spectacle might delight the similarly-inclined, the goal here is to learn together. To ignore that is simply rude.
“There was no treachery too base for the world to commit.”
— Virginia Woolf, 1927
I had heard the word perfidious long before I understood it. It was one of those terms that floated in the air of educated disapproval — an appropriately dressed up term of reproach. I knew what it meant, or thought I did: faithless, not to be trusted. It dripped of reproach.
What I did not know — until just last week — was that perfidy is not merely a moral judgment but a legal one. Not a flourish. A term of art.1
In the law of war, perfidy describes a very specific offense: the use of deception to induce an enemy to believe you are protected under the laws of war — civilian, wounded, medical, or surrendering — and then killing them once they rely on it.
In other words, it names a crime committed not just against an opponent, but against the idea that rules mean anything at all. Perfidy is one of the most serious violations of the laws governing the use of military forces.
That led, as it almost always does, down a rabbit hole. This one was tinged with words for wickedness, and I thought we might explore some polite terms for disgraceful conduct together.
A Lexicon of Disrepute
Treachery
Treachery refers to a deliberate and willful act of betraying trust and confidence. It signifies a conscious decision to violate a reliance or faith that was placed in someone. Examples include corporate espionage, betraying a business partner or financial misconduct.2
Knavery
Knavery refers to dishonest or unscrupulous behavior—acts of trickery, deceit, or fraud. While it may sound somewhat archaic or literary, knavery represents a concept that is still in active practice.
For example, in politics, gerrymandering could be considered knavery, as electoral districts are manipulated to favor one party. In finance, contract knavery refers to deceptive practices in loan contracts where terms are added that unfairly harm the borrower, often without their awareness. And Ponzi schemes employ deceit for financial gain.
Skulduggery
Also spelled “skullduggery,” it is underhanded or unscrupulous behavior, or a devious device or trick. The word originated from Scottish slang in the early 19th century, rooted in the idea of sneaky tricks or fraudulent dealings, often with a connotation of mischief or illicit activity.3
Villainy
Often implying more serious crimes or evil deeds, Merriam-Webster defines villainy as “the quality or state of being villainous : depravity.” Villainy and depravity abound of late.
Lèse-majesté: Treason and Sedition
The category of lèse-majesté is a crime committed against a sovereign power. Not the kind of crime like kidnapping a leader of a sovereign nation, but crimes like treason and sedition, which are two sides of the same coin.
Treason reason involves acts against one’s own country, while sedition refers to inciting rebellion against the government.4
Avarice / Rapaciousness
Both of these are associated with greed. Avarice is excessive or insatiable desire for wealth or profit, while rapacious is excessively grasping or covetous, to the point of being ravenous. As one might appear if one placed stolen assets in an offshore account, charged $1 billion for a membership fee, or decked out an office in gold.
Machination
A scheming or crafty action or artful design intended to accomplish some usually evil end. Something a cabal — or a board — might do.
Vituperation
When one vituperates, they’re uttering sustained and bitter railing and condemnation. Sometimes it may be well-grounded; other times, it may be delusional and completely outside of the realm of reality.
Impudent
Impudence is marked by contemptuous or cocky disrespect of others, expressed in very rude and insolent behavior. It is commonly seen in sociopathic narcissists.
Well, I hope this journey on the dark side has been elucidating for you.
I think it was apparent to quite a few people across the globe this week as well.
There’s so much to learn,
“Even accepting the Trump administration’s claim that there is an armed conflict with suspected drug runners, the laws of war bar ‘perfidy.’”: “U.S. Attacked Boat With Aircraft That Looked Like a Civilian Plane,” The New York Times, January 12, 2026
Falsifying business records is a good example of this.
“Skulduggery meaning and exmaples,” e-grammar book