Rheostat

Part of speech: noun

Pronunciation: /ˈɹiː.ə.stat/

Definitions

1. An electrical component that modulates current flow by varying resistance within a circuit
2. A device that adjusts electrical current by changing the resistance in a circuit
3. An electrical instrument used to control the amount of current via resistance variation

Etymology: Charles Wheatstone, the English physicist and inventor, coined this term in an 1843 journal article, building it from Greek parts that describe what the device does: it makes a flow of electricity stationary, or steady, by adjusting resistance. The first part comes from the Greek "rhéō," meaning "to flow, stream," which traces back to a reconstructed ancient root meaning the same thing. Wheatstone was not drawing on an ancient word for an electrical device, since none existed; he assembled a fresh technical name from classical materials. The second part, "-stat," comes from the Greek "-státēs," an agent suffix tied to "hístēmi," "to stand" or "to stop." Scientists used this ending to name instruments meant to hold something in one state, so the pairing of "rheo-" with "-stat" signals a device that keeps current steady rather than letting it run freely.

Synonyms: variable resistor, controller, regulator, resistor, dimmer