nodule

American  

[noj-ool] / ˈnɒdʒ ul /

noun

1. a small node, knot, or knob.

2. a small, rounded mass or lump.

3. Botany. a tubercle.

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nodule British  

/ ˈnɒdjuːl /

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

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nodule Scientific  

/ nŏj′o̅o̅l /

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.

3. See more at legume

4. 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.

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Other Word Forms

• nodular adjective

Etymology

Origin of nodule

1590–1600; < Latin nōdulus a little knot, equivalent to nōd ( us ) node + -ulus -ule

Explanation

A nodule is a small, raised bump under the skin. You might notice a nodule on the top of your foot after spraining your ankle. Any solid bump or node that you can feel just beneath your skin is a nodule. You may have noticed nodules in your neck when you have a sore throat or a nodule on your shin where you bumped it into the coffee table. Another kind of nodule is very similar, but appears on a plant's surface. The Latin root word is nodulus, "small knot," from nodus, or "knot."

Example Sentences

Another limitation is having an incidental finding, such as a lung nodule.

From The Wall Street Journal • Mar. 30, 2026

The leftover sediment and fine nodule fragments are then released back into the ocean.

From Science Daily • Nov. 8, 2025

The discovery was made after the Democrat politician reported urinary symptoms which led doctors to find a small nodule on his prostate.

From BBC • Oct. 11, 2025

The diagnosis occurred last week, following a urinary screening that revealed a small nodule in his prostate, which revealed the aggressive Stage 4 prostate cancer, according to the statement.

From Slate • May 20, 2025

“Right,” he said, and gripped a golden nodule that protruded from the trunk.

From "Impossible Creatures" by Katherine Rundell

Related Words

• growth
• knot
• node