non-appearance
/ˌnɒnəˈpɪərəns/noun
mass noun
1- failure to appear or be present, especially at a gathering or engagement（尤指在聚会、约会中）未露面; 缺席。
1.1
- Law failure to appear or be present in a court of law, especially as a witness, defendant, or plaintiff【律】（尤指证人、被告、原告的）缺席, 未到庭。