look up any word, like timebomb:
 
1.
'tween forty and fifty
Zac Efron: I guess all my fans aren't tweens
Fred Armisen: Well I'm a twifty.
Zac Efron: A twifty?
Fred Armisen: 'tween forty and fifty
by mojojojo12333 April 22, 2009
 
2.
A twifty is a person in their fifties who acts like they're in their twenties. Some dude who gets high at rock concerts when he should be sitting at home in an armchair watching Masterpiece Theater Classic.
Dude you see that twifty over there?
Yeah?!
Dude, what a twifty.
by Cool2Snog May 15, 2010
 
3.
Twifties are the fun people around age 50 and UP. The derivation is "Fifty is the new Twenty. Twenty, Fifty, ...Twifty."

The word was created to describe the most active, vital subset of the Baby Boomers and older, a group often wrongly ignored by marketers who stick to the old model of capturing the 18 to 34 age group. Created by professional wordsmith Lauren Teton in NY in 2008.
Dude, you're going to a music festival/hiking/bowling with your mother? No worries, she's cool, she's one of the Twifties!
by LaurenTT August 04, 2010
 
4.
The number that lies half way between twenty and fifty...Or thirty five.
Dude, your milf sister is hot. How old is she?
She's twifty.

Dude, you haven't been missing any meals lately. How many lb's you sportin?
Bout two twifty.
by big cu October 18, 2006