| HAD | Hong Kong Dragon Airlines Limited | 港龙航空公司 |
| HAD | Heat-Actuated Device | 感温式火灾探测装置 |
| HAD | Halmstad, Sweden - Halmstad (Airport Code) | 瑞典哈尔姆斯塔德-哈尔姆斯塔（机场代码） |
| HAD | Hemadsorption (laboratory virus testing) | 血液吸附（实验室病毒检测） |
| HAD | Halmstad, Sweden | 瑞典哈尔姆斯塔德 |
| HAD | Hole Accumulated Diode (Sony) | 空穴累积二极管（索尼） |
| HAD | Human Aspects Development | 人的方面发展 |
| HAD | Heinemann Australian Dictionary | 海涅曼澳大利亚词典 |
| HAD | Hearing Aid Dealer | 助听器经销商 |
| HAD | Heated Air Ducting | 加热空气管道 |
| HAD | Human Athletic Dance | 人类竞技舞蹈 |
| HAD | Hole Accumulated Diode | 空穴累积二极管 |
| HAD | Hear All Dragons | 倾听所有的龙 |
| HAD | Haloacid Dehalogenase | 卤酸脱卤酶 |
| HAD | hospital administrator | 医院管理员 |
| HAD | hospital admininstration | 医院管理 |
| HAD | hypophysectomized alloxan diabetic | 垂体切除四氧嘧啶糖尿病 |
| HAD | hexamethylmelamine,adriamycin(doxorubicin),and cis-diamminedichloroplatinum(cisplatin) | 六甲基三聚氰胺、阿霉素（阿霉素）和顺铂（顺铂） |
| HAD | Homeland Air Defense | 国土防空 |
| HAD | Heat Activated Device | 热激活装置 |
| HAD | Horizontal Acoustic Depiction | 水平声学描述 |
| HAD | hydroxydopamine | 羟多巴胺 |
| HAD | Harness Assembly Drawing (electrical wire assembly drawing for manufacturing of cable harness assemblies) | 线束装配图（用于制造电缆线束组件的电线装配图） |
| HAD | High Aluminum Defect | 高铝缺陷 |
| HAD | 3-Hydroxyacyl-CoA Dehydrogenase (deficiency) | 3-羟基酰基-CoA脱氢酶（缺乏） |
| HAD | Health Assessment Document | 健康评估文件 |
| HAD | Hubble Data Archive | 哈勃数据档案 |
| HAD | Hospital Anxiety Depression | 医院焦虑抑郁 |
| HAD | Heat Acquisition Devices | 热量采集装置 |
| HAD | Headbangers Against Disco | 反对迪斯科的头槌 |
| HAD | Hardware Data Acquisition | 硬件数据采集 |
| HAD | Home Affairs Department (Hong Kong) | 民政事务署（中国香港） |
| HAD | Hole Accumulation Diode (Sony) | 空穴累积二极管（索尼） |
| HAD | Atlantic Haddock | 大西洋黑线鳕 |
| HAD | High Availability Device | 高可用性设备 |