A piece of work to be done.

• A duty or assignment.
• A difficult or tedious undertaking.
• A specific objective to achieve.

A process or unit of work in computing.

• An executing program or scheduled job.

Archaic: a tax or charge.

To assign a task to someone.

• To require someone to do work.

Literary: to burden heavily; to tax.

• To charge or reproach with a fault.