rotary

American  

[roh-tuh-ree] / ˈroʊ tə ri /

adjective

1. turning or capable of turning around on an axis, as a wheel.

2. taking place around an axis, as motion.

3. having a part or parts that turn on an axis, as a machine.

---

noun

• rotaries
  plural

1. a rotary device or machine.

2. Chiefly Northeastern U.S. traffic circle.

3. Also called rotary converter.  Electricity. synchronous converter.

4. (initial capital letter) Rotary Club.

rotary British  

/ ˈrəʊtərɪ /

adjective

1. of, relating to, or operating by rotation

2. turning or able to turn; revolving

---

noun

1. a part of a machine that rotates about an axis

2. a roundabout (for traffic)

Other Word Forms

Derived Forms

• unrotary
  adjective

Inflected Forms

Nouns

• rotaries
  plural

Etymology

Origin of rotary

1725–35; < Medieval Latin rotārius (adj.), equivalent to Latin rot ( a ) wheel + -ārius -ary

Explanation

Anything rotary has a circular form, like an old-fashioned phone. A rotary is also a traffic circle. Just as the Earth rotates around the sun, rotary objects move in a circle or orbit. A rotary telephone has a circular dial that turns, and a rotary mower has a cutting blade that moves in a circular motion. A type of street where traffic flows in a circle — sometimes called a roundabout — can also be called a rotary. The word stems from the Latin word rotarius, "pertaining to wheels," from its root word rota, or "wheel."

Example Sentences

See Examples For:

rotary rotaries

Lockheed said it had higher volumes and munitions ramp ups across all its units, including aeronautics, missiles and fire control, space, and rotary and mission systems.

From The Wall Street Journal ● Jul. 23, 2026

But what was once a small memorial is now just the base of an old rotary phone without the handset.

From Los Angeles Times ● Jul. 6, 2026

To the west in Duarte, an old tan rotary phone with a very long cord hangs on a tree in a garden.

From Los Angeles Times ● Jul. 6, 2026

A startup called LiquidPiston has spent more than a decade developing a new kind of rotary engine—including the X Mini shown here—that it says can be both more efficient and compact than traditional piston engines.

From The Wall Street Journal ● Apr. 24, 2026

General Peckem rose and moved toward a rotary rack of enormous colored maps.

From "Catch-22" by Joseph Heller

But he also sees a unique set of challenges in Boston, pointing to a city that’s “not gridded” and has “windy streets, poor weather, lots of roundabouts or rotaries, crazy intersections.”

From Slate ● Jun. 21, 2018

Little details would amaze him, like touch-tone phones that replaced the bulky rotaries everyone had used when he went away.

From Washington Times ● Apr. 4, 2015

Farther south along Main, past a couple more rotaries, you’ll find Manchester Village.

From New York Times ● Jan. 31, 2014

Signs and public-service announcements have taught Americans how to negotiate their new rotaries.

From Economist ● Oct. 3, 2013

A sudden gush of clear, cold air came through the ventilation valves as the triple rotaries started up with a roar.

From The Sky Trap by Frank Belknap Long