| Abbreviation | Definition |
|---|---|
| ENSA | Economics of National Security Association |
| ENSA | Edinburgh Napier Students Association |
| ENSA | Entertainment National Service Association |
| ENZSA | Edmonton North Zone Soccer Association (Canada) |
| EOA | Eastern Ohio Association |
| EOA | Egyptian Orthopaedic Association |
| EOA | Essential Oil Association |
| EOCA | European Outdoor Conversation Association |
| EOIA | Equal Opportunities Initiative Association |
| EORA | Eastern Outdoor Reps Association |
| EOSA | Eastern Ontario Swimming Association |
| EOSA | Ely Outdoor Sports Association |
| EOSA | Ethylene Oxide Sterilization Association |
| EOUA | Eastern Ontario Umpires Association |
| EPA | Ethiopian Pharmaceutical Association |
| EPA | European Psychiatric Association |
| EPA | Evangelical Press Association |
| EPAF | Extension Professional Associations of Florida |
| EPAI | Exmoor Pony Association International |
| EPAI | EZine Publishers Association International |