a worker: the person who does the labor of a task, whether hired for a field or shop or, by extension, laboring in God's service
At its root the word names anyone who does the physical work of a job: the day laborer hired for the vineyard, the field hand who brings in the harvest, the silversmith at his bench. By itself it says nothing about status or wages. It simply marks the person as the one doing the work. It overlaps with the hired hand (μισθωτός), but that word stresses being paid while this one stresses the doing.
The New Testament repeatedly lifts this everyday word into a picture of gospel work. Jesus calls the crowds a ripe harvest and the ministers who gather them "workers," too few for the field (Matthew 9:37-38). The same image becomes a working rule: "the worker deserves his wages," meaning those who labor at teaching should be supported. A minister who handles Scripture well is "a worker who has no need to be ashamed." It sits close to the servant or minister (διάκονος), but that word frames the role as service while this one frames it as labor.
Because the word is a compliment, the writers can also turn it against people. Paul brands rival missionaries "deceitful workers" and "evil workers," men who labor hard at spreading a false message. And in one place it slides toward an old scriptural phrase, "workers of iniquity," where the thing being worked at is wrongdoing itself rather than a trade.