| Acronym | Definition |
|---|
| BAK | Backup (File Name Extension) |
| BAK | Backspace |
| BAK | Bundesarchitektenkammer |
| BAK | Backup File |
| BAK | Broadcast Access Key |
| BAK | Back At Keyboard |
| BAK | Bundesamt für Kultur (German: Federal Office for Culture; Switzerland) |
| BAK | Biking Across Kansas (bicycle tour) |
| BAK | Bauartklasse (German insurance term) |
| BAK | Berliner Arbeitskreis Information (German) |
| BAK | Basic Aeronautical Knowledge |
| BAK | Betrayal At Krondor (computer game) |
| BAK | Bundesaufsichtsamt für das Kreditwesen (German banking supervisory board) |
| BAK | Baku, Azerbaijan - Baku (Airport Code) |
| BAK | Blut Alkohol Konzentration (German: blood alcohol level) |
| BAK | Binary Adaption Kit |
| BAK | Beitragsanpassungsklausel (German; legal insurance) |
| BAK | Bosomtwe-Atwima-Kwanwoma (district; Ghana) |
| BAK | Bewußtsein, Atmung, Kreislauf |
| BAK | Bouviers d'Australie et des Kelpies (French: Australian Kelpie and Cattle Dog; dog club) |
| BAK | Barrier Arresting Kit |
| BAK | Bilateral Above Knee (amputation) |
| BAK | Biohybrid Artificial Kidney |