What is an antonym for supercalifragilisticexpialidocious?

It's tricky to find a true antonym for "supercalifragilisticexpialidocious" because it's a made-up word intended to convey extreme happiness and excellence. There isn't a single word that directly contradicts those feelings.

However, here are some options depending on what aspect you want to contradict:

* For "happiness": Miserable, depressing, unpleasant, awful.

* For "excellence": Terrible, horrible, atrocious, worthless.

* For "fantastic": Dreadful, abysmal, lousy, dismal.

Ultimately, the best antonym depends on the specific context and the feeling you're trying to evoke.