noun (n)

• Dutch astronomer who calculated the size of the universe and suggested that it is expanding (1872-1934)(noun.person)

  Synonym:
  willem de sitter
  

  source: wordnet30
• an organism (person or animal) that sits(noun.person)

  Antonym:
  stander
  

  source: wordnet30
• a person engaged to care for children when the parents are not home(noun.person)

  Synonym:
  baby-sitter, babysitter
  

  source: wordnet30
• a person who poses for a painter or sculptor(noun.person)

  source: wordnet30
• a domestic hen ready to brood(noun.animal)

  Synonym:
  brood hen, broody, broody hen, setting hen
  

  source: wordnet30
• One who sits; esp., one who sits for a portrait or a bust.(noun)

  source: webster1913