n (uncountable|physics) A measure of energy expended in moving an object; most commonly, force times distance. No work is done if the object does not move.
n (uncountable|thermodynamics) A nonthermal First Law energy in transit between one form or repository and another. Also, a means of accomplishing such transit.[http://arxiv.org/pdf/physics/0004055 See http://arxiv.org/pdf/physics/0004055].