Source : Webster's Revised Unabridged Dictionary (1913)

Idorgan \Id*or"gan\, n. [Gr. ? form + E. organ.] (Biol.)
   A morphological unit, consisting of two or more plastids,
   which does not possess the positive character of the person
   or stock, in distinction from the physiological organ or
   biorgan. See {Morphon}.