organ

a fully differentiated structural and functional unit in an animal that is specialized for some particular function

a government agency or instrument devoted to the performance of some specific function; "The Census Bureau is an organ of the Commerce Department"

(music) an electronic simulation of a pipe organ

a periodical that is published by a special interest group; "the organ of the communist party"

wind instrument whose sound is produced by means of pipes arranged in sets supplied with air from a bellows and controlled from a large complex musical keyboard

a free-reed instrument in which air is forced through the reeds by bellows