Gibberish is nonsensical speech or writing that sounds like it might mean something but actually doesn't. When your little brother babbles “blibber blabber boop bop” and pretends he's speaking another language, that's gibberish. When someone types “asdfjkl;” by running their fingers across a keyboard, they're creating written gibberish.

The word often describes what happens when someone tries to explain something they don't really understand. A student who didn't study might produce gibberish on an essay test, stringing together random vocabulary words that sound impressive but make no sense. Sometimes people intentionally speak gibberish to be silly or to mock someone who isn't being clear.

You might also use gibberish to criticize confusing instructions or overcomplicated explanations: “These directions are complete gibberish!” means they're so poorly written that they're useless.

The key to gibberish is that it has the form of language without the substance: it might have the rhythm of normal speech or look like real sentences, but when you actually pay attention, there's no real meaning hiding underneath all those sounds or letters.