ETYM Greek ergon work.
Unit of work measuring force of one dyne applied over one centimeter
A cgs unit of work or energy; the work done by a force of one dyne acting over a distance of one centimeter.
Unit of energy: equal to the work done by a force of one dyne in moving its point of application one centimeter in the direction of that force.
C.g.s. unit of work, replaced in the SI system by the joule. One erg of work is done by a force of one dyne moving through one centimeter.