| COTD | Cult of the Dolphin | 海豚崇拜 |
| COTD | Cache of the Day (geocaching) | 每日缓存（地理存储） |
| COTD | City of the Dead | 死亡之城 |
| COTD | Coaltar of the Deepers (Japan band) | 更深的海岸（日本乐队） |
| COTD | Cardiac Output Obtained by Thermodilution | 通过热稀释获得的心输出量 |
| COTD | cardiac output by thermodilution | 热稀释法心输出量 |
| COTD | Catch Of The Day | 一天中的收获 |
| COTD | Cat of the Day | 每日最佳猫 |
| COTD | Cotangent of x in Degrees | x余切（度） |
| COTD | Card Of The Day | 当天的名片 |
| COTD | Circle of True Doom | 真正的末日之圈 |
| COTD | Call Off the Dogs | 叫停狗 |
| COTD | Comment of the Day | 当天的评论 |
| COTD | City of the Damned | 被诅咒的城市 |