What does rotary mean?
Rotary is an adjective describing something that turns, revolves, or operates by rotation around a fixed axis. It is widely used in technical and industrial contexts, as in rotary engine, rotary switch, rotary mower, and rotary drill. The related noun refers to a machine or mechanism driven by rotation, especially a rotary engine. In ordinary English, the word often suggests mechanical motion and, by extension, the continuous turning associated with machinery. “Rotary” is also used in the name Rotary International, referring to the worldwide organization of service clubs. When capitalized as part of “Rotary club,” it identifies a local branch of that organization. Although the word can describe any rotating mechanism, it is particularly associated with engines, switches, cutting tools, lawn mowers, and older telephones with rotating dials. In these uses, rotary contrasts with mechanisms that move in a straight line or remain stationary.
Involving or designed for rotation around an axis; turning or revolving.
"The technician replaced the damaged rotary switch."
A machine or device that operates by rotation, especially an engine or mechanical apparatus.
"The rotary powered the generator at the construction site."
This noun use is less common than the adjective and is most often encountered in technical or historical descriptions.
Usually refers to multiple rotary machines or devices, though the plural is relatively uncommon in modern general usage.
"The factory produced several rotaries for agricultural use."
From the Latin rotare, meaning “to turn,” rotary describes the everyday engineering principle behind wheels, engines, turbines, and even old-fashioned telephone dials.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does rotary come from?
The word comes through Latin rotare, meaning “to turn,” and ultimately relates to the same root found in rotate and rotation. It entered English in the early 19th century, when mechanical engineering and rotary devices were becoming increasingly important. The Latin root also appears in related words such as rotunda, referring to a round building with a domed or rotating interior arrangement, and rotative, meaning relating to rotation.
Related word forms
How rotary is actually used
“Rotary” is common as a technical adjective in engineering and manufacturing. As a noun, it is comparatively uncommon and often refers to a rotary engine or machine. The capitalized form “Rotary” is also used for the international service organization Rotary International and its local clubs.
Easily confused with rotary
Rotate is a verb meaning to turn around an axis, while rotary is usually an adjective describing something that turns or operates by rotation.