Acquittal, n.
1. The act of acquitting; discharge from debt or obligation; acquittance.
2. (Law)
A setting free, or deliverance from the charge of an offense, by verdict of a jury or sentence of a court. Bouvier.
Shades of meaning
Fernald has no entry of its own for acquittal; he lists it under pardon.
Where he writes about it:
Acquittal is a release from a charge, after trial, as not guilty. — from pardon
Acquittal is by the decision of a court, commonly of a jury; pardon is the act of the executive. — from pardon
An innocent man may demand acquittal, and need not plead for pardon. — from pardon