harmonium Meaning, Definition & Usage

  1. noun a free-reed instrument in which air is forced through the reeds by bellows
    reed organ; organ.

WordNet

Har*mo"ni*um noun
Etymology
NL. See Harmony.
Definitions
  1. A musical instrument, resembling a small organ and especially designed for church music, in which the tones are produced by forcing air by means of a bellows so as to cause the vibration of free metallic reeds. It is now made with one or two keyboards, and has pedals and stops.

Webster 1913