- a small node, knot, or knob.
- a small, rounded mass or lump.
- Botany. a tubercle.
- a small knot, lump, or node
- Also called: root nodule any of the knoblike outgrowths on the roots of clover and many other legumes: contain bacteria involved in nitrogen fixation
- anatomy any small node or knoblike protuberance
- a small rounded lump of rock or mineral substance, esp in a matrix of different rock material
n.early 15c., from Latin nodulus “small knot,” diminutive of nodus “knot” (see net (n.)). Related: Nodulated; nodulous; nodulation. n.
- A small node.
- A small mass of tissue or aggregation of cells.
- A small, usually hard mass of tissue in the body.
- 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.
- 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.