Hallucination
When an AI model states something confidently that is not true, such as inventing a cost figure instead of fetching it from a tool. It is most likely when the model answers from its own guesswork rather than calling the data source it has access to. Why it matters: A made-up number in a cost report can drive a wrong decision, so figures should be checked against the source.
Read the term in context.
Each row is a lesson that uses this term. The lesson where it first appears is the canonical definition.