[choir] n [ME quer, fr. MF cuer, fr. ML chorus, fr. L, chorus--more at chorus] (14c) 1: an organized company of singers (as in a church service)
2: a group of instruments of the same class "a brass ~"
3: an organized group of persons or things
4: a division of angels
5: the part of a church occupied by the singers or by the clergy; also: the part of a church where the services are performed
6: a group organized for ensemble speaking
[2]choir vi (1596): to sing or sound in chorus or concert