Tuber = Main Entry: tu·ber
Pronunciation: ‘tü-b&r, ‘tyü-
Function: noun
Etymology: Latin, swelling, truffle; perhaps akin to Latin tumEre to swell — more at THUMB
1 a : a short fleshy usually 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

YouTuber = http://www.youtube.com/watch?v=VXwarrIYLJ4