Yes, you can give any name you want when you define the font family in the @font-face style declaration and use that name to reference it later in the stylesheet.
@font-face
{
font-family: whateverYouWant;
src: url('example.ttf'),
url('example.eot');
... /* and so on */
}
Whatever you name the style as in the font-family property is how it will be referred to from the rest of the document. However I don't know how it competes with local font files (so if you tried to name a custom font Arial I'm not sure what you would get - the custom font or the real Arial). I don't know why you would do that anyway though.