nodule

noun

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

noun

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

n.early 15c., from Latin nodulus “small knot,” diminutive of nodus “knot” (see net (n.)). Related: Nodulated; nodulous; nodulation. n.

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

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.