What is Not Guilty?

Legal Definition
Pleading. The general issue in several sorts of actions. It is the general issue.

2. In trespass, its form is as follows: "And the said C D, by E F, his attorney, comes and defends the, force and injury, when, &c., and says, that he is not guilty of the said trespasses above laid to his charge, or any part thereof, in the mannor and form as the said A B hath above complained. And of this the said C D puts himself upon the country."

3. Under this issue the defendant may give in evidence any matter which directly controverts the truth of any allegation, which the plaintiff on such general issue will be bound to prove; 1 B. & P. 213; and no person is bound to justify who is not, prima facie, a trespasser. 2 B. & P. 359: 2 Saund. 284, d. For example, the plea of not guilty is proper in trespass to persons, if the defendant have committed no assault, battery, or imprisonment, &c.; and in trespass to personal property, if the plaintiff had no property in the goods, or the defendant were not guilty of taking them, &c.; and in trespass to real property, this plea not only puts in issue the fact of trespass, &c , but also the title, which, whether freehold or possessory in the defendant, or a person under whom he claims, may be given in evidence under it, which matters show, prima facie, that the right of possession, which is necessary in trespass, is not in the plaintiff, but in the defendant or the person under whom he justifies. 8 T. R. 403; 7 T. R. 354; Willes, 222; Steph. PI. 178; 1 Chit. PI. 491, 492.

4. In trespass on the case in general, the formula is as follows: " And the said C D, by E F his attorney, comes and defends the wrong and injury when, &c., and says, that he is not guilty of the premises above laid to his charge, in manner and form as the said A B hath above complained. And of this the said C D puts himself on the country."

5. This, it will be observed, is a mere traverse, or denial, of the facts alleged in the declaration; and therefore, on principle, should be applied only to cases in which the defence rest's on such denial. But here a relaxation has taken place, for under this plea, a defendant is permitted not only to contest the truth of the declaration, but with some exceptions, to prove any matter of defence, that tends to show that the plaintiff has no cause of action, though such matters be in confession and avoidance of the declaration; as, for example, a release given, or satisfaction made. Steph. Pl. 182-3; 1 Chit. Pi. 486.

6. In trover. It is not usual in this action to plead any other plea, except the statute of limitations; and a release, and the bankruptcy of the plaintiff, may be given in evidence under the general issue. 7 T. R. 391

7. In debt on a judgment suggesting a devastavit, an executor may plead not guilty. 1 T. R. 462.

8. In criminal cases, when the defendant wishes to put himself on his trial, he pleads not guilty.
-- Bouviers Law Dictionary
Legal Definition
A pica of the general issue in the actions of trespass and case and in criminal prosecutions. The form of the verdict in criminal cases, where the jury acquit the prisoner. 4 BL Comm. 361.
-- Black's Law Dictionary
Legal Definition
The general issue in trespass and certain other civil actions; a plea denying the allegations of a criminal charge; the form of a verdict of acquittal. See 50 W. Va. 644, 88 Am. St. Rep. 909, 57 L. R. A. 428, 41 S. E. 190.
-- Ballentine's Law Dictionary