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[nuh-frid-ee-uh m] /nəˈfrɪd i əm/
noun, plural nephridia
[nuh-frid-ee-uh] /nəˈfrɪd i ə/ (Show IPA).
the excretory organ of many invertebrates, consisting of a tubule with one end opening into the body cavity and the other opening into a pore at the body surface.
1875-80; < New Latin; see nephr-, -idium
Related forms
nephridial, adjective Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
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British Dictionary definitions for nephridium


noun (pl) -ia (-ɪə)
a simple excretory organ of many invertebrates, consisting of a tube through which waste products pass to the exterior
Derived Forms
nephridial, adjective
Word Origin
C19: New Latin: little kidney
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
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Word Origin and History for nephridium

(plural nephridia), 1877, Modern Latin, from Greek diminutive of nephros "kidney" (see nephron).

Online Etymology Dictionary, © 2010 Douglas Harper
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nephridium in Medicine

nephridium ne·phrid·i·um (nə-frĭd'ē-əm)
n. pl. ne·phrid·i·a (-ē-ə)
The embryonic excretory organ from which the kidney develops.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
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Encyclopedia Article for nephridium

unit of the excretory system in many primitive invertebrates and also in the amphioxus; it expels wastes from the body cavity to the (usually aquatic) exterior. The evolution of nephridia encouraged tissue specialization by eliminating the need for all cells of an organism to be in contact with seawater for diffusion of metabolic wastes.

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Encyclopedia Britannica, 2008. Encyclopedia Britannica Online.
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