noun (n)

• a person who works at a specific occupation(noun.person)

  Example:
  He is a good worker.
  

  Antonym:
  nonworker
  

  source: wordnet30
• a member of the working class (not necessarily employed)(noun.person)

  Example:
  Workers of the world--unite!.
  

  Synonym:
  prole, proletarian
  

  source: wordnet30
• sterile member of a colony of social insects that forages for food and cares for the larvae(noun.animal)

  source: wordnet30
• a person who acts and gets things done(noun.person)

  Example:
  He's a miracle worker.
  

  Synonym:
  actor, doer
  

  source: wordnet30
• One who, or that which, works; a laborer; a performer; as, a worker in brass.(noun)

  source: webster1913