a small node, knot, or knob.
a small, rounded mass or lump.
Botany. a tubercle.

1590–1600; < Latin nōdulus a little knot, equivalent to nōd(us) node + -ulus -ule Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2014.
Cite This Source Link To nodules
World English Dictionary
nodule (ˈnɒdjuːl)
1.  a small knot, lump, or node
2.  Also called: root nodule any of the knoblike outgrowths on the roots of clover and many other legumes: contain bacteria involved in nitrogen fixation
3.  anatomy any small node or knoblike protuberance
4.  a small rounded lump of rock or mineral substance, esp in a matrix of different rock material
[C17: from Latin nōdulus, from nōdus knot]

Collins English Dictionary - Complete & Unabridged 10th Edition
2009 © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009
Cite This Source
Word Origin & History

1600, from L. nodulus "small knot," dim. of nodus "knot."
Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
American Heritage
Medical Dictionary

nodule nod·ule (nŏj'ōōl)

  1. A small node.

  2. A small mass of tissue or aggregation of cells.

nod'u·lar (nŏj'ə-lər) or nod'u·lose' (-lōs') or nod'u·lous (-ləs) adj.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source
American Heritage
Science Dictionary
nodule   (nŏj'l)  Pronunciation Key 
  1. A small, usually hard mass of tissue in the body.

  2. A small, knoblike outgrowth found on the roots of many legumes, such as alfalfa, beans, and peas. Nodules grow after the roots have been infected with nitrogen-fixing bacteria of the genus Rhizobium. See more at legume.

  3. A small, rounded lump of a mineral or mixture of minerals that is distinct from and usually harder than the surrounding rock or sediment. Nodules often form by replacement of a small part of the rocks in which they form.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
Cite This Source
Example sentences
But despite millions of dollars of investment, the commercial extraction of
  manganese nodules never became reality.
During such an infection, inflamed nodules within the membranes create pressure
  on the bone surface, leaving the lesions.
Little nodules of calcium form in this gland and then go to the gizzard and
  help grind up food.
From afar, it is a single block of plastic with nodules on the top.
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature