arm

We usually think of an "arm" as the body part extending from the shoulder to the hand—used for reaching, lifting, carrying, and hugging. But "arm" has a broader meaning. It can also refer to something that extends outward like an arm, providing support or reach: the arm of a chair, the arm of a crane, the arms of a river, or the arms of a galaxy.

It can also be about weapons and preparation. As a noun, arms often means "weapons" (“to take up arms”). As a verb, to arm someone is to give them weapons (“to arm the guards”), and to arm a device or system is to make it ready to work (“to arm the alarm”). It’s a surprisingly versatile word!

The most familiar meaning of "arm" is the limb extending from the shoulder to the hand—essential for movement, manipulation, and feeling. We use our arms for countless daily tasks, from writing and eating to embracing loved ones. "She injured her arm playing volleyball."

However, "arm" extends beyond anatomy. It can describe anything resembling an arm in shape or function: a projecting part offering support or leverage. Consider the arm of a sofa, providing a place to rest your elbow; the arm of a scale balance, measuring weight; or even the arms of a hurricane, swirling outwards from its center. However, "arm" extends beyond anatomy. It can describe anything resembling an arm in shape or function: a projecting part offering support or leverage. Consider the arm of a sofa, providing a place to rest your elbow; the arm of a balance scale, measuring weight; or even the arms of a hurricane, swirling outward from its center.

In another common sense, arms (usually plural) means "weapons" in general, especially in older or more formal language: “to lay down your arms,” “to be up in arms,” or “small arms.” Related to that, "arm" can be used as a verb meaning to equip someone with weapons or supplies for conflict. To "arm" soldiers is to provide them with what they need to fight. You might hear about countries arming themselves, or a knight being armed for jousting.

"Arm" can also mean “make ready to operate,” especially for devices and security systems: you arm a bomb, a trap, or an alarm—meaning you set it so it will go off when triggered (the opposite is disarm).

Finally, "arm" can refer to a branch of a larger organization (“the research arm of the company,” “the enforcement arm of the state”), where the idea is something that reaches out and acts on behalf of the whole.

The word also appears in compound words like "armchair," "armistice" (a truce), and "arms race."

So whether it's a body part, a supporting structure, or the act of preparing for battle, "arm" is a word that speaks to reach, support, and power.