executor

noun4

1. •
   A person who carries out some task.
2. •
   Someone appointed by a testator to administer their estate in accordance with their will; an administrator.

   • Mary Ann Mead (executor of James Mead deceased,) of Aurora, Ia., for improvements in packing and pressing cotton. — 1847
3. •
   A component of a system that executes or runs something.

   • When searching for a solution is unnecessary, then the program executor "doesn't care" which solution is generated nor how it is obtained. — 2014
4. •
   (no longer used) An executioner.

   • The sad-eyed justice, with his surly hum, / Delivering o'er to executors pale / The lazy yawning drone. — 1599