[bak-stop] 
noun, verb, -stopped, -stop⋅ping.| 1. | a wall, wire screen, or the like, serving to prevent a ball from going too far beyond the normal playing area. |
| 2. | Baseball. the catcher. |
| 3. | a person or thing that serves as a support, safeguard, or reinforcement: There were technicians on board as backstops to the automated controls. |
| 4. | to act as a backstop. |
| 5. | to act as a backstop to: The government agreed to backstop companies that invested in oil exploration. |
