| Abbreviation | Definition |
|---|---|
| MECA | MN Erosion Control Association |
| MECA | Mobile Electronics Competition Association |
| MECA | MS Educational Computing Association |
| MEDA | McDowell Economic Development Association |
| MEEA | Middle East Economic Association |
| MEHNA | Manufacturers of Equipment for Heat Networks Association |
| MEIBA | Middle East International Baccalaureate Association |
| MELA | Metro East Landlords Association |
| MELSA | Medical English Learning Support Association |
| MELSA | Middle Eastern Law Student Association |
| MELSA | Middle Eastern Law Students Association |
| MEMA | Machinery and Equipment Manufacturers Association |
| MEMA | Metropolitan Emergency Managers Association |
| MEMA | Motor & Equipment Manufacturers Association |
| MENTA | Maintaining and Establishing a National Trainee Association |
| MEPA | Missouri Emergency Preparedness Association |
| MEQA | Middle East Quality Association |
| MERA | Motor Equipment Remanufacturers Association |
| MESANA | Middle East Studies Association of North America |
| MESSA | Middle Eastern Studies Students' Association |