worker

noun4

1. •
   a person who is paid to do a job, often one done with the hands and body

   • Fret not thy selfe because of euill doers, neither bee thou enuious against the workers of iniquitie. — 1611
2. •
   A nonreproductive social insect, such as ant, bee, termite, or wasp.
3. •
   (rare) A female ant, bee, termite or wasp.
4. •
   A thread performing one instance of a particular task within a program.

   • This FTP client spawns a separate worker for each file to be uploaded.