or·gan (ôr?g?n)n.1. Music a. An instrument consisting of a number of pipes that sound tones when supplied with air and a keyboard that operates a mechanism controlling the flow of air to the pipes. Also called pipe organ.b. Any one of various other instruments, such as the electronic organ, that resemble a pipe organ either in mechanism or sound.2. Biology A differentiated part of an organism, such as an eye, wing, or leaf, that performs a specific function.3. An instrument or agency dedicated to the performance of specified functions: The FBI is an organ of the Justice Department.4. An instrument or means of communication, especially a periodical issued by a political party, business firm, or other group.[Middle English, from Old French organe and from Old English organe, both from Latin organum, tool, instrument, from Greek organon; see werg- in Indo-European roots.]American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.organ (?????n) n1. (Instruments) a. Also called: pipe organ a large complex musical keyboard instrument in which sound is produced by means of a number of pipes arranged in sets or stops, supplied with air from a bellows. The largest instruments possess three or more manuals and one pedal keyboard and have the greatest range of any instrumentb. (as modifier): organ pipe; organ stop; organ loft. 2. (Instruments) any instrument, such as a harmonium, in which sound is produced in this way. See also reed organ, harmonica3. (Instruments) short for electric organ1a, electronic organ4. (Biology) a fully differentiated structural and functional unit, such as a kidney or a root, in an animal or plant5. an agency or medium of communication, esp a periodical issued by a specialist group or party6. an instrument with which something is done or accomplished7. a euphemistic word for penis[C13: from Old French organe, from Latin organum implement, from Greek organon tool; compare Greek ergein to work]Collins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014or?gan (??r g?n) n. 1. a. Also called pipe organ. a musical instrument having one or more sets of pipes actuated by keyboard and sounded by compressed air. b. a similar musical instrument having the tones produced electronically: an electronic organ. c. reed organ. d. barrel organ. e. hand organ. 2. a grouping of tissues into a distinct structure, as a heart or kidney in animals or a leaf or stamen in plants, that performs a specialized task. 3. a newspaper, magazine, or other means of communicating information, thoughts, or opinions, esp. in behalf of some organization or political group. 4. an instrument or means, as of action. 5. penis. [before 1000; Middle English: musical instrument, pipe organ, organ of the body, tool « Greek órganon implement, tool, bodily organ, musical instrument, akin to érgon work] Random House Kernerman Webster’s College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.or·gan (ôr?g?n) A distinct part of an organism that performs one or more particular functions. Examples of organs are the eyes, ears, lungs, and heart of an animal, and the roots, stems, and leaves of a plant.The American Heritage® Student Science Dictionary, Second Edition. Copyright © 2014 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.organ – Comes from Latin organum, from Greek oganon, “implement, instrument, tool”; it was first a very general term, but was then used for “wind instrument” and “functional part of the body.”See also related terms for wind instrument.Farlex Trivia Dictionary. © 2012 Farlex, Inc. All rights reserved.organ1. A structure composed of several tissues that performs a specific function, e.g. stomach, leaf.2. Part of the body made of different tissues that performs a particular task.Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited