| MEFF | Mercado Español de Futuros Financieros (Financial Futures Spanish Market) | Mercado Español de Futuros Financieros (Financial Futures Spanish Market) |
| MEFF | Marine Electronics Fire Fighting | 船舶电子消防 |
| MEFF | Multicultural Eid Festival and Fair (Sydney, Australia) | 多文化开斋节和集市（澳大利亚悉尼） |
| MEFF | Most Esteemed First Finder (geocaching) | 最受尊敬的First Finder（地理缓存） |
| MEFF | Mercado de Futuros Financieros | 未来金融市场 |