early 15c., "payment of debt or retribution;" see acquit + -al (2). Sense of "a release from debt or obligation" is from mid-15c.; that of "freeing from charge or offense" (by legal process) is from 1530s.
1. The jury voted 8-to-4 in favor of acquittal.
2. The case resulted in an acquittal.
3. The defence lawyer made an eloquent plea for his client's acquittal.
4. He was released from prison following his acquittal.