Meaning

noun the cardinal number that is the sum of nineteen and one

noun a United States bill worth 20 dollars

adjective denoting a quantity consisting of 20 items or units

originFrom Middle English twenty, twenti, from Old English twēntiġ (“twenty”, literally “two tens”), from Proto-Germanic *twaintigiwiz, *twai tigiwiz, an old compound of *twain- (“two”) + *-tigaz (“group of ten”), equivalent to two + -ty, or twain + -ty. Cognate with Scots twenty, tuenty (“twenty”), West Frisian tweintich (“twenty”), Dutch twintig (“twenty”), German zwanzig (“twenty”), Danish tyve.

Etymology from Wiktionary, CC BY-SA 3.0