* Nonsense words: Like "blibble-blibble" or "flibbertigibbet".
* Random combinations of letters: Like "xyzzpq" or "qwert".
* Language that is unintelligible due to a foreign accent or speech impediment: It can be hard to understand someone who speaks very quickly, has a strong accent, or has a stammer.
* A jumbled mix of real words with no grammatical sense: Like "The sky blue car ran fast."
* Deliberately nonsensical language used for humor or entertainment: Think of children's rhymes or Dr. Seuss.
Essentially, gibberish is anything that sounds like language but doesn't actually convey a clear meaning.