Someone who is somewhere in their late teens through early twenties, when they know everything and are absurdly idealistic.
I can't wait until he is no longer a tweenty and not such a d-bag.
by alm4400 December 26, 2010
1 more definition
The second decade of the 21st Century from 2010 to 2020 in between the Aughts (or The Aughties) & The Twenties. It's a portmanteau of the words tween, teen, and twenties.
Lady Gaga's career launched in the first decade of the new millennium, but will her popularity & influence on music prolong throughout the Tweenties?
by johnnydiva January 20, 2011