The innocent man was wrongly imprisoned for 20 years, which was a clear miscarriage of justice.

miscarriage 由前缀 mis-（表示"错误的"）和 carriage（"运送、承载"）组成，字面意思是"错误运送"。 justice 指"正义、司法"。 miscarriage of justice 是固定短语，指"司法不公"，特指司法机关错误判决导致无辜者被定罪的情况。