Worker (noun)

1. A person who does manual or industrial labor, typically as a member of a workforce.
2. A person who is employed to do a particular job or task.
3. An active and efficient person.
4. A member of a trade union or other organization representing the interests of workers.
5. An organism that actively performs a function, such as a bee or ant in a colony.

Origin:

Middle english: from work + -er.

Examples:

1. The factory employs a large number of workers.
2. She is a skilled worker in the field of medicine.
3. He is a hard worker and always finishes his tasks on time.
4. The workers went on strike to protest their working conditions.
5. Worker bees gather nectar and pollen to bring back to the colony.