Joule
/dʒuːl/noun
The SI unit of energy, work, or heat.
Did you know?The joule is an eponym, named for physicist James Prescott Joule, whose experiments helped prove that heat and mechanical work are interchangeable forms of energy.
Etymological Timeline
1870s
English
joule
“A proposed and then standardized unit of energy and work in the metric system”
1870s
French
joule
“Scientific unit name adopted in metrology”
19th Century
English
Joule
“The surname of physicist James Prescott Joule”
Old French
French
Joule
“A family name, ultimately from a medieval personal name”
Late Latin
Latin
Iulius
“The Roman family name Julius”