Real Dictionary

rub
verb: If you rub a part of your body, you move your hand or fingers backwards and forwards over it while pressing firmly.
verb: If you rub against a surface or rub a part of your body against a surface, you move it backwards and forwards while pressing it against the surface.

rub in American English
to move one's hand, a cloth, etc. over (a surface or object) with pressure and friction, in a circular or back-and-forth motion
intransitive verb: to exert pressure and friction on something
transitive verb: to subject the surface of (a thing or person) to pressure and friction, as in cleaning, smoothing, polishing, coating, massaging, or soothing

rub in British English
verb: to apply pressure and friction to (something) with a circular or backward and forward motion