FRIC'TION, n. [L. frictio, frico, to rub.]

1. The act of rubbing the surface of one body against that of another; attrition. Many bodies by friction emit light, and friction generates or evolves heat.

2. In mechanics, the effect of rubbing, or the resistance which a moving body meets with from the surface on which it moves.

3. In medicine, the rubbing of the body with the hand, or with a brush, flannel, &c.; or the rubbing of a diseased part with oil, unguent or other medicament.