[tu.ber] n [L, swelling, truffle; perh. akin to L tumere to swell--more at thumb] (1668) 1 a: a short fleshy usu. underground stem bearing minute scale leaves each of which bears a bud in its axil and is potentially able to produce a new plant--compare bulb, corm b: a fleshy root or rhizome resembling a tuber
2: an anatomical prominence: tuberosity