Science & TechnologyGreek → English
Rheostat
/ˈriːə(ʊ)stat/noun
A variable resistor used to control the current in a circuit.
The Greek roots
ῥέος
rhéos
stream, flow
στατός
statós
standing, set
Literally: “flow-steadier”
The story of the word
Charles Wheatstone coined the name in 1843 for a device meant to hold a current steady against changing conditions, literally to make the flow stand still. Everyday use inverted the intention, since the thing people remember rheostats for is dimming lights and slowing motors. The same root flows through rheumatism, once blamed on humours streaming through the body, and rheology, the science of how matter deforms.
- How it travelled
- Ancient Greek → English coinage
- First recorded
- 1843
Same family
rheologyrheumcatarrhthermostatstatic
In a sentence
A rheostat under the bench let him ease the voltage up by hand.
The stage lights ran off a bank of rheostats until the 1970s.