/twen"tee, twun"-/ , n. , pl. twenties , adj.
n.
1. a cardinal number, 10 times 2.
2. a symbol for this number, as 20 or XX.
3. a set of this many persons or things.
4. Informal. a twenty-dollar bill: Can you give me two tens for a twenty?
5. twenties , the numbers, years, degrees, or the like, from 20 through 29, as in referring to numbered streets, indicating the years of a lifetime or of a century, or referring to degrees of temperature: He lives in the West Twenties. She's in her early twenties. The temperature must be in the high twenties today.
adj.
6. amounting to 20 in number.
[ bef. 900; ME; OE twentig; c. OFris tw ( e ) intich, OHG zweinzug (G zwanzig ), Goth twai tigjus two tens ]