Rotary

Part of speech: adjective

Pronunciation: /ˈɹəʊtəɹi/

Definitions

1. Connected with or involving circular motion or rotation ; a machine or mechanism that moves by turning around an axis ; a type of engine design where components rotate to generate power
2. Pertaining to movement in a circle or around a central point ; a device operating by spinning or revolving parts ; an engine that utilizes rotating rotors instead of pistons
3. Involving turning or spinning action as in movement or operation ; a mechanical device that rotates to perform work ; an engine where rotating elements replace traditional reciprocating parts

Etymology: Before it described spinning machinery, "rotary" meant something close to its Latin root's plain sense of wheel-shaped. The word comes from Medieval Latin "rotarius," itself built on the classical Latin "rota," meaning "wheel." The Latin root has given English a family of wheel words, including "rotate" and "rotation," but the adjective "rotary" was not attested in English until the mid 18th century, when it was used for things that turn around a central axis. The adjective's real importance came later, when engineers applied it to machines whose parts revolve rather than reciprocate. A rotary engine or rotary telephone dial is defined by that circular motion, which is why the word stayed attached to wheels and axles even as its uses multiplied. The core idea has changed little since the 1700s: something that moves round a fixed centre.

Synonyms: circular, revolving, spinning