Definition of joule in English:


(also J)


  • The SI unit of work or energy, equal to the work done by a force of one newton when its point of application moves one metre in the direction of action of the force, equivalent to one 3600th of a watt-hour.

    • ‘They reckon it would release two billion joules of energy.’
    • ‘The unit of absorbed dose is call the gray, which is the amount of energy in joules from the radiation absorbed per kilogram of the absorbing material.’
    • ‘One calorie of heat is equivalent to 4.2 joules of work.’
    • ‘One joule of output energy will energise approximately 6 miles of wire with no interference.’
    • ‘And a joule is indeed a sensible sort of unit in everyday life - a 60-watt lightbulb radiates 60 joules of energy every second.’


Late 19th century: named after J. P. Joule(see Joule, James Prescott).