#volunteer__unpaid_worker  a person who performs voluntary work
  supertype:  worker  a person who works at a specific job; "he is a good worker"
  subtype:  candy_striper__candystriper  a volunteer worker in a hospital
  subtype:  pledge_taker  a volunteer who records (usually by telephone) contributions pledged in a fund drive
  subtype:  vigilante__vigilance_man__vigilanceman  member of a vigilance committee

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