arbitrary

The word "arbitrary" describes something done without a clear system, reason, or principle. It suggests a decision made at random, based on personal preference, or simply because someone in power decided it should be so. Think of it as the opposite of "justified" or "logical."

Historically, "arbitrary" comes from the Latin arbitrarius, meaning "depending on one's will." This gets at its core meaning: something determined by individual choice rather than objective, external standards. This is why, in a legal or political sense, "arbitrary power" is often used to describe a ruler who ignores the law and acts solely on their own impulses.

You might describe a rule as arbitrary if it seems pointless or inconsistent. For example: "The office dress code seemed completely arbitrary—why were sleeveless shirts banned while shorts were allowed?" In this context, the word implies that the rule lacks a sensible foundation.

It is important to distinguish "arbitrary" from "random." While both involve a lack of predictability, arbitrary often implies an exercise of human will or authority. A "random" event happens by pure chance, like rolling dice. An "arbitrary" event is dictated by someone's choice, even if that choice seems to have no "rhyme or reason" behind it.

Another very common use is closer to “any” or “chosen freely.” When someone says “Pick an arbitrary example” or “Let x be an arbitrary number,” they mean the choice doesn’t matter to the point being made: it’s not special, and there’s no particular reason to prefer one over another. Similarly, in math and science you’ll hear about an “arbitrary origin,” an “arbitrary scale,” or “arbitrary units,” meaning the reference point is set by convention or convenience rather than being uniquely determined by nature.

So, when something feels like it has been pulled out of thin air—driven by subjectivity rather than facts—it is likely arbitrary. It highlights the influence of individual preference over structured logic.