Definitions from Black's Law Dictionary: 2nd Edition and Ballentine's Law Dictionary as are available for each term in each dictionary.
  • Ballentine's Law Dictionary

    At once.

  • Black's Law Dictionary: 2nd Edition

    Immediately; instantly; forthwith; without delay. Trial instanter was had where a prisoner between attainder and execution pleaded that he was not the same who was attainted. When a party is ordered to plead instanter, he must plead the same day. The term is usually understood to mean within twenty-four hours. Rex v. Johnson, 6 East, 583; Smith v. Little, 53 III. App. 160; State v. Clevenger, 20 Mo. App. 627; Fentress v. State, 16 Tex. App. 83; Champlin v. Champ-lin, 2 Edw. Ch. (N. Y.) 329.