noun

• (law) A group of individuals chosen from the general population to hear and decide a case in a court of law.
  "And so the jury and he approached, as if this were a time of peace instead of one of the greatest world disturbances ever known in history, the question whether the prosecution had proved to the jury’s satisfaction that George Joseph Smith was guilty of murder. The jury were the shield which stood between him and death, unless, to the jury’s satisfaction, he was proved to be guilty. Yet while they were the shield of the man accused, they were also the Sword of the State; and if the man were proved guilty, they were the servants of the State to punish him. Their respective functions were these: he the judge, had to settle the law, and the jury must take the law from him. The jury were judges of fact."
• (theater, slang) The audience attending the first night of a performance, whose reaction may determine whether it succeeds or fails.
  "The jury which decides on the first night usually seals the fate of the season."

adj

• (nautical) For temporary use; applied to a temporary contrivance.
  "jury mast"