chorus

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A group of singers who perform together, usually singing multi-part compositions with more than one singer for each part.
• noun A group of vocalists and dancers who support the soloists and leading performers in operas, musical comedies, and revues.
• noun A musical composition usually in four or more parts written for a large number of singers.
• noun A refrain in a song, especially one in which the soloist is joined by other performers or audience members.
• noun A solo section based on the main melody of a popular song and played by a member of the group.
• noun A group of persons who speak or sing in unison a given part or composition in drama or poetry recitation.
• noun An actor in Elizabethan drama who recites the prologue and epilogue to a play and sometimes comments on the action.
• noun A group in a classical Greek drama whose songs and dances present an exposition of or, in later tradition, a disengaged commentary on the action.
• noun The portion of a classical Greek drama consisting of choric dance and song.
• noun A speech, song, or other utterance made in concert by many people.
• noun A simultaneous utterance by a number of people.
• transitive & intransitive verb To sing or utter in chorus.
• idiom (in chorus) All together; in unison.

from The Century Dictionary.

• To sing or join in the chorus of: as, to chorus a song.
• To exclaim or call out in concert.
• noun A dance. Specifically, in the ancient Greek drama— A dance performed by a number of persons in a ring, in honor of Bacchus, accompanied by the singing of the sacred dithyrambic odes. From this simple rite was developed the Greek drama, In continuation of the early tradition, a company of persons, represented as of age, sex, and estate appropriate to the play, who took part through their leader, the coryphæus, with the actors in the dialogue of a drama, and sang their sentiments at stated intervals when no actor was on the stage.
• noun One of the songs executed by the chorus.
• noun In music: A company of singers, especially an organized company, such as singers in a church or a choral society, In an oratorio, opera, or concert, the general company of singers, as distinguished from the soloists, A part of a song in which the listeners join with the singer; a refrain; also, any recurring refrain or burden, A musical composition intended to be sung in harmony by a company of singers, usually by four voices. A double chorus is for eight voices, The compound or mixture stops of an organ. In the tenth century, an instrument, probably the bagpipe, In the fifteenth century, the drone of a bagpipe or of the accompaniment strings of the crowd. Formerly, in Scotland, a loud trumpet.
• noun A union of voices or sounds, or a company of persons, resembling a chorus.
• noun In zoology, a genus of mollusks.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Antiq.) A band of singers and dancers.
• noun (Gr. Drama) A company of persons supposed to behold what passed in the acts of a tragedy, and to sing the sentiments which the events suggested in couplets or verses between the acts; also, that which was thus sung by the chorus.
• noun obsolete An interpreter in a dumb show or play.
• noun (Mus.) A company of singers singing in concert.
• noun (Mus.) A composition of two or more parts, each of which is intended to be sung by a number of voices.
• noun (Mus.) Parts of a song or hymn recurring at intervals, as at the end of stanzas; also, a company of singers who join with the singer or choir in singer or choir in singing such parts.
• noun The simultaneous of a company in any noisy demonstration.
• intransitive verb To sing in chorus; to exclaim simultaneously.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A group of singers and dancers in the religious festivals of ancient Greece
• noun A group of people in a play or performance who recite together.
• noun A group of singers; singing group who perform together.
• noun A repeated part of a song, also called the refrain.
• noun A setting or feature in electronic music that makes one voice sound like many.
• noun figuratively A group of people or animals who make sounds together
• noun theater An actor who reads the opening and closing lines of a play.
• verb To echo a particular sentiment.
• verb To sing the chorus.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• verb utter in unison
• noun any utterance produced simultaneously by a group
• noun the part of a song where a soloist is joined by a group of singers
• noun a group of people assembled to sing together
• verb sing in a choir
• noun a company of actors who comment (by speaking or singing in unison) on the action in a classical Greek play
• noun a body of dancers or singers who perform together