The Collaborative International Dictionary of English v.0.48:
Choir \Choir\, n. [OE. quer, OF. cuer, F. ch[oe]ur, fr. L.
chorus a choral dance, chorus, choir, fr. Gr. ?, orig.
dancing place; prob. akin to ? inclosure, L. hortus garden,
and E. yard. See Chorus.]
1. A band or organized company of singers, especially in
church service. [Formerly written also quire.]
2. That part of a church appropriated to the singers.
3. (Arch.) The chancel.
Choir organ (Mus.), one of the three or five distinct
organs included in the full organ, each separable from the
rest, but all controlled by one performer; a portion of
the full organ, complete in itself, and more practicable
for ordinary service and in the accompanying of the vocal
Choir screen, Choir wall (Arch.), a screen or low wall
separating the choir from the aisles.
Choir service, the service of singing performed by the
choir. --T. Warton.