D defs.my
Entry 1 sense Webster, 1913

Harmonium

/(här*mō"nĭ*ŭm)/ · Har·mo·ni·um · IPA /hɑɹˈmoʊ̯.ni.əm/
01 n. A musical instrument, resembling a small organ and especially designed for church music, in which the tones are produced by forcing air by …
  1. 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.