Verb
To touch something with one's body.
She accidentally rubbed up against the painted door and got green paint on her blouse.
To touch another person with one's body in a sexually stimulating manner.
(of animals) To touch a person's body in a friendly manner, seeking attention.
Tibbles the cat rubbed up against my leg, asking for a piece of my cheese.
To come into conflict with someone or something.
Source: en.wiktionary.orgIt's no secret that in my books I'm trying to make the comic and the serious rub up against each other just as closely and uncomfortably as I can. Richard Russo
There is a piece of me that likes to fondly imagine my maverick and rebellious nature, but, more accurately, I like to have a nice and cosy institution that I can rub up against a little bit. Douglas Adams