What is the meaning of chorus?

noun

• Any utterance produced simultaneously by a group.
  • usage: "a chorus of boos"
• A group of people assembled to sing together.
• The part of a song where a soloist is joined by a group of singers.
  • synonyms: refrain
• A body of dancers or singers who perform together.
  • synonyms: chorus line
• A company of actors who comment (by speaking or singing in unison) on the action in a classical Greek play.
  • synonyms: Greek chorus

verb

• Utter in unison.
  • usage: "`yes,' the children chorused"
• Sing in a choir.
  • synonyms: choir