Grounding
Tying a model's answer to a trusted source — documents, a database, search results — so it reports what the source says instead of what merely sounds plausible. The main defence against made-up answers.
ⓘ Technical definition
Conditioning generation on retrieved, authoritative context (documents, tools, knowledge bases) so outputs are attributable to a source. Underlies RAG and citation systems; reduces but does not eliminate hallucination.