noun (n)

• someone who listens attentively(noun.person)

  Synonym:
  auditor, hearer, listener
  

  source: wordnet30
• someone who waits on or tends to or attends to the needs of another(noun.person)

  Synonym:
  attendant, tender
  

  source: wordnet30
• a person who is present and participates in a meeting(noun.person)

  Example:
  He was a regular attender at department meetings.
  

  Synonym:
  attendant, attendee, meeter
  

  source: wordnet30
• One who, or that which, attends.(noun)

  source: webster1913