tu·ber (tbər, ty-)
a. A swollen, fleshy, usually underground outgrowth of the stem or rhizome of a plant, such as the potato, bearing buds from which new plant shoots arise.
b. A similar outgrowth of a plant root.
2. A rounded projection or swelling; a tubercle.
[Latin tūber, lump; see teuə- in the Appendix of Indo-European roots.]
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