In the context of a jury trial, the term unsafe verdict refers to a judicial finding that a jury's guilty verdict is unsafe and should be overturned.
Unsafe means that the verdict or conviction was not based on reliable evidence and is likely to constitute a miscarriage of justice.
In most common law jurisdictions, people convicted at jury trial are allowed to have the evidence and transcript of their trial reviewed by an appellate court.
Verdicts can be found to be unsafe for either legal or factual reasons.