noun

organ

A keyboard instrument that produces sustained tones through pipes or electronics.

The organ fills the church with rich, steady musical tones.

Etymology

Greek organon means a tool or instrument. The general instrument name became specialized to the keyboard instrument that sustains sound through pipes or their electronic equivalents.

More examples

She practices on an electronic organ at home.
The organ's pedals let the player sound low notes using both feet.
An organ can sustain a note as long as a key stays pressed.

Forms

organ · organs

organist noun — A musician who plays the organ.

Similar words

piano: Produces struck-string tones that fade rather than remain sustained.
synthesizer: Can imitate an organ but also creates many other sounds.