choir organ

Century Dictionary and Cyclopedia

1. n. In large organs, the third principal section of the instrument, of less power than the great organ, and containing stops specially suited for choir accompaniment. Once called the chair-organ; occasionally, also, the positive organ.

GNU Webster's 1913

1. n. (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.