| Abbreviation | Definition |
|---|---|
| CWIU | Chemical Workers Industrial Union |
| CWJ | Center for Worker Justice |
| CWLU | Chicago Women's Liberation Union |
| CWU | Cambrian Werewolves Union |
| CWU | Civil Workers Union |
| CWU | Communication Workers Union |
| CWU | Communications Workers Union |
| CWUA | Confectionery Workers' Union of Australia |
| CWUSA | Creative Workers Union of South Africa |
| CZU | Cleveland Zeppelin Union |
| DAC | Drivers And Carriers |
| DAWU | Dominica Amalgamated Workers' Union |
| DBAA | Discount Buyers Association of America |
| DBAA | Durbans Bluff Accommodation Association |
| DBSU | Dalit Bahujan Shramik Union |
| DBU | Dansk Boldspil Union |
| DBU | Dutch Burger Union |
| DC | Diners Club |
| DCCU | Dane County Credit Union |
| DCCU | Delta County Credit Union |