The term 'JOULE FRACTION' is a combination of two words, 'JOULE' and 'FRACTION'. JOULE is a unit of energy, named after the English physicist James Prescott JOULE. A FRACTION is a part of a whole, usually expressed as a ratio or a decimal. The JOULE FRACTION is the amount of energy that is converted into work when a force of one newton is applied over a distance of one meter. The crossword solution for this term is 'ERG', which is a unit of energy equal to one JOULE.