Webster's Revised Unabridged Dictionary · 1913

Tuber

Tuber , noun

[Latin, a hump. knob; probably akin to tumere to swell. Compare Tumid.]

1.
(a) (Botany) A fleshy, rounded stem or root, usually containing starchy matter, as the potato or arrowroot; a thickened root-stock. See Illust. of Tuberous.
(b)
(Botany) A genus of fungi. See Truffle.
2.
(Anatomy) A tuberosity; a tubercle.