What's a good english word that means busy yet empty?

Politician?

I doubt that there is a single word to convey your meaning – not one that I can recall. You might have to settle for a phrase. There are lots of those.

Oxymoronic? Homework?

Not homework, just to express what I’m feeling.

Fidgety.

The phrase ”running in place” kind of captures that image. @unodos Is there a Spanish word that has this meaning?

Alongs those line, the phrase “spinning my wheels” means activity without productivity. Another one, “going through the motions” means that you are doing what you have to do, but without any energy or feeling behind it. Is this the feeling you are trying to convey?

Tedious?

Another phrase that captures the spirit of what you are looking for is ”ladies who lunch.”

Edit: “Along those lines” – (I think better than I type .)

fatuous

Donald Trump?

Paris Hilton?

II know your language questions are always serious, @unodos, so let me be clear on what you mean.

Are you looking for a single English word that has two opposite meanings? Two examples of that would be cleave and sanction. In any one use, the word has only one meaning or the other, not both, and the context determines it.

Or are you after a word for the specific case you mention?—that is, a word for a self-contradictory state such as moving quickly but going nowhere?

If the latter, there may be single words with that sort of meaning, but I can’t think of them. To describe a person or situation in such a state, we would usually resort to a phrase, sometimes a literal phrase (“rushing but going nowhere”) or an idiom (“all in a flurry”), but more likely to be a metaphorical expression such as those suggested above (“spinning his wheels”).

@Harp has a good suggestion. If there is a Spanish word that has the meaning you intend, let us help translate and look for English equivalents. If there are only idioms and no single literal words, probably some of our bilingual members can help there too.

Spinning your wheels.

“Spinning your wheels” was the phrase that came to my mind. “Hurry up and wait” is another, though not exactly right.

I can’t come up with anything more clever than @DarkScribe‘s politician. Brilliant!

@Supacase: Festina lente- (Lat.) – make haste slowly.

The French call a certain appearance “une jolie laide.” I have always loved that.

Dichotomy would describe division into two usually contradictory parts or opinions, such as good and evil coexisting in a person.

@gailcalled & @PandoraBoxx tres nice.

If you’re looking for a term for the category of words that can have two different meanings that are opposites of each other, the word for that is “contranyms.” There’s another Fluther discussion about that here

At this point, it would be nice to hear from the OP because we don’t quite know what he is looking for as Jeruba said.

a good phrase was spinning my wheels.