[kawl-bak] 
| 1. | an act of calling back. |
| 2. | a summoning of workers back to work after a layoff. |
| 3. | a summoning of an employee back to work after working hours, as for emergency business. |
| 4. | a request to a performer who has auditioned for a role, booking, or the like to return for another audition. |
| 5. | recall (def. 12). |
| 6. | a return telephone call. |
| 7. | of or pertaining to such a call: Please leave a callback number. |
| call-back | |
noun | |
| 1. | a return call |
| 2. | the recall of an employee after a layoff |