Hallucination
Also called AI hallucination.
A hallucination is AI-generated information that is false or unsupported even when the response sounds confident.
Example
A bot names a court case that does not exist while summarizing a contract. The summary sounds finished. The case name is a hallucination.
Why it matters
The wording can be grammatical and specific and still not match the source you gave, or any source. Confidence in the tone is not evidence. Checking the claim against the material you trust is the useful next step.
Common confusion
A hallucination is not a creative choice you requested, such as a fictional story. It is an unsupported claim presented as if it were known.
Sources
Updated September 30, 2026.