a person engaged in a particular field, activity, or cause: a worker in psychological research; a worker for the Republican Party.
Entomology. a member of a caste of sexually underdeveloped, nonreproductive bees, specialized to collect food and maintain the hive. a similar member of a specialized caste of ants, termites, or wasps.
Printing. one of a set of electrotyped plates used to print from (contrasted with molder).