Noun
The act of rubbing the surface of one body against that of another; attrition; in hygiene, the act of rubbing the body with the hand, with flannel, or with a brush etc., to excite the skin to healthy action.
The resistance which a body meets with from the surface on which it moves. It may be resistance to sliding motion, or to rolling motion.
A clashing between two persons or parties in opinions or work; a disagreement tending to prevent or retard progress.
Source: Webster's dictionary