| Acronym | Definition |
|---|
| ZEI➣ZEI, Inc. (not and acronym; formerly Zinder Engineering, Inc.) |
| ZEI➣Zenith Enterprises, Inc. (investment advisor; California) |
| ZEI➣Zone d'Epuration Individuelle (French: Area of Individual Purification; wastewater treatment; Belgium) |
| ZEI➣Zentrum für Europaische Integrationsforschung (German: Center for European Integration Research; est. 1995) |
| ZEI➣Zero Error Information |