Splitting a main navigation menu item to two lines

I'd like to know if I can get menu items to display on 2 lines.

For example I'd like       About Us

to be on 2 lines like this:

About
Us

Thank you!

Hi
in the menu item options you can set the "description", this is a text that will take place on the 2nd line, as example you can look at my website joomlack.fr

CEd