1. A part of an organism that is typically self-contained and has a specific vital function, such as the heart or liver in humans.
For some time, the Guinness Book people thought that all the world's oldest (biological) organs were contained within one person: a 122-year-old French woman named Jeanne Calment, who died in 1997. (There may have been older people in the world, but Calment had the papers to prove her age.) Recently, however, a comparatively sprightly 80-year-old fellow in Norway did her one better: it was discovered that Bernt Aune had a cornea transplant in 1958, an organ that had been harvested from the cadaver of an elderly man born in 1885 -- making Aune's cornea 123 years old (last year anyway) -- the oldest in the world. So how well does Aune see through his antique cornea? "My vision's not great," he says.
2. A large musical instrument having rows of tuned pipes sounded by compressed air, and played using one or more keyboards to produce a wide range of musical effects.
3. A medium of communication, esp. a newspaper or periodical that serves a particular organization, political party, etc. : the People's Daily, the official organ of the Chinese Communist Party.