rub 
(rŭb)
(rŭb)v. rubbed, rub·bing, rubs
v.tr.
1. To apply pressure and friction to (a surface).
2. To clean, polish, or manipulate by the application of pressure and friction.
3. To apply to a surface firmly and with friction: rub lotion on the hands; rub dye into the fabric.
4. To move (an object or objects) firmly along a surface, especially repeatedly: rub an eraser over the blackboard; rubbed my fingers over the sore spot.
5. To cause to become worn, chafed, or irritated.
6. To remove, erase, or expunge: rub away a stain; rubbed the sleep from my eyes.
v.intr.
1.
a. To exert pressure or friction on something.
b. To wear or chafe with friction: My shoes were beginning to rub.
c. To cause irritation or annoyance.
2. To move along in contact with a surface; graze or scrape.
3. To be transferred or removed by contact or proximity: newsprint that rubbed off on my fingers; wished some of her luck would rub off on me.
n.
Phrasal Verbs: 1. The act of rubbing.
2. The application of friction and pressure: a back rub.
3. A substance or preparation applied by rubbing, especially:
a. A liniment or balm.
b. A seasoning made of ground spices and herbs, applied to the surface of meat, fish, or vegetables before cooking.
4. An unevenness on a surface.
5. An act or remark that annoys or hurts another.
6. A difficulty or obstacle: "The rub for extraterrestrial life on Europa is that the moon's surface is an icy wasteland" (William J. Broad).
rub down
To perform a brisk rubbing of the body, as in massage.
rub in
To harp on (an unpleasant matter).
rub out
Idioms: 1. To obliterate by or as if by rubbing.
2. Slang To kill; murder.
rub elbows/shoulders
To mix or socialize closely: diplomats rubbing elbows with heads of state.
rub (one's) hands
To experience or display pleased anticipation, self-satisfaction, or glee.
rub (someone's) nose in Slang
To bring repeatedly and forcefully to another's attention.
rub (someone) the wrong way
To annoy; irritate: "One can see ... how [his] expression of his ideals and intentions must have rubbed many people the wrong way" (Christopher Lehmann-Haupt).
rub up on
To refresh one's knowledge of: I have to rub up on my French.
[Middle English rubben.]