Grand jury

Etymology

From Anglo-French "grand" (large) and "jury" (from Latin "jurare," to swear), so named because it was historically larger than the "petit" (small) trial jury. The pairing of "grand" and "petit" survives directly from the French legal vocabulary of medieval England.

noun phrase · /GRAND JOOR-ee/
A panel of citizens that decides whether there is enough evidence to formally charge someone with a crime.
What it names
The gatekeeping jury that comes before any trial — deciding whether to accuse, not whether to convict.
Example
The grand jury heard only the prosecutor’s evidence and voted to indict, sending the case toward trial.
Related idea
A grand jury decides whether to charge, hearing one side in secret; a trial jury decides guilt, hearing both sides in open court — one opens the case, the other closes it.