Other forms: organs
An organ is a working part inside a body, each with one job: the heart pumps, the lungs take in air, the liver cleans the blood. Organ donor, organ transplant, internal organs — the word appears whenever a body is described part by part.
The other organ is the instrument: rows of pipes in a church, a keyboard at the bottom, and a sound big enough to fill the building. A church organ, a pipe organ, an organist at the console, the electric organ on a seaside pier. A third use is formal — an organ is an official body, or the newspaper that speaks for one: an organ of the state, the party's official organ. Do not reach for organic as the adjective; it means grown without chemicals, or made of living matter. For the body sense the noun does the work itself: organ failure, organ donation.
1nounorganA part of the body with a particular function, such as the heart or the liver.
“The liver is the only organ that can regrow after part of it is removed.”
synonyms: body part
2nounlargeA large keyboard instrument that makes sound by driving air through pipes.
“The organ started up and the whole church seemed to shake.”
3nounofficialAn official body, or a newspaper that speaks for one.
“The paper was for years the official organ of the trade union movement.”
Both organs are one word. Greek organon meant a tool or an instrument — anything you work with — and Greek already used it for a part of the body and for a musical instrument alike. Latin took it as organum, and English received it twice, once through Old English and again through Old French. The root behind it is the one that also gave work and energy: an organ is a thing that does work.
Middle English
organe
English, today
organ
From Middle English organe. From Middle English organe, from Old French organe and Old English organ, both from Latin organum, from Ancient Greek ὄργανον (“an instrument, implement, tool, also an organ of sense or apprehension, an organ of the body, also a musical instrument, an organ”), from Proto-Indo-European werǵ-. a doublet of organon and organum and orgue.
Etymology from Wiktionary, CC BY-SA