tuber

¹ American  

[too-ber, tyoo-] / ˈtu bər, ˈtyu- /

noun

1. Botany. a fleshy, usually oblong or rounded thickening or outgrowth, as the potato, of a subterranean stem or shoot, bearing minute scalelike leaves with buds or eyes in their axils from which new plants may arise.

2. Anatomy. a rounded swelling or protuberance; a tuberosity; a tubercle.

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tuber ² American  

[too-ber, tyoo-] / ˈtu bər, ˈtyu- /

noun

1. a person or thing that forms, installs, or operates with tubes.

2. Also called inner-tuber.  a person who participates in the sport of tubing.

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tuber British  

/ ˈtjuːbə /

noun

1. a fleshy underground stem (as in the potato) or root (as in the dahlia) that is an organ of vegetative reproduction and food storage

2. anatomy a raised area; swelling

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tuber Scientific  

/ to̅o̅′bər /

1. The thickened part of an underground stem of a plant, such as the potato, bearing buds from which new plant shoots arise.

2. Compare bulb corm rhizome runner

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Other Word Forms

Derived Forms

• tuberoid
  adjective
• tuberless
  adjective

Etymology

Origin of tuber¹

1660–70; < Latin tūber bump, swelling. Cf. truffle

Origin of tuber²

First recorded in 1920–25; tube + -er ¹

Explanation

A tuber is a plant that mainly grows underground. Potatoes and yams are tubers — and they're delicious with a little butter and salt. The part of a potato plant that can be eaten is its thickened underground stem — and officially, that's the part of the plant considered a tuber. Potatoes are a stem tuber, while sweet potatoes are root tubers. There are slight differences in the way these different types of tubers grow new plants, but they're all basically edible roots. In Latin the word tuber means "edible root," but also "lump, bump, or swelling."

Example Sentences

What appears to have started as one man’s idea of a joke has spread in recent years, with more households offering the tuber in an effort to give the festivities a topsy-turvy spin.

From The Wall Street Journal • Oct. 30, 2025

The movie starts in fictional Chuglass, Idaho, the “potato chip capital of America,” where a giant tuber mascot looms over the town.

From Los Angeles Times • Apr. 2, 2025

For potatoes, maybe, but probably for something else decisively outside of the tuber realm.

From Salon • Feb. 28, 2024

This chimeric tuber is the interface where Balanophora steals nutrients from its host plant.

From Science Daily • Sep. 21, 2023

The skins seemed to slip off easily enough for Aunty Ifeoma, but when I pressed one end of a tuber, the rough brown skin stayed put and the heat stung my palms.

From "Purple Hibiscus" by Chimamanda Ngozi Adichie