twen‧ty /ˈtwenti/ number, noun
[Language: Old English; Origin: twentig]

1. the number 20:
a small village twenty miles from Nairobi
I’m nearly twenty (=20 years old).

2. the twenties [plural] (also the 20s, the 1920s) the years from 1920 to 1929:
In the twenties the business expanded.
the early/mid/late twenties
The photograph was taken in the late twenties.

3. be in your twenties to be aged between 20 and 29
early/mid/late twenties
She was in her early twenties when I met her.

4. in the twenties if the temperature is in the twenties, it is between 20 degrees and 29 degrees
in the low/mid/high twenties
a warm day, with temperatures in the low twenties

5. [countable] a piece of paper money that is worth £20 or $20:
I offered the driver a twenty.
—twentieth adjective, pronoun:
in the twentieth century
her twentieth birthday
I’m planning to leave on the twentieth (=the 20th day of the month).

[TahlilGaran] Dictionary of Contemporary English ▲

Twen‧ty20 /ˌtwenti ˈtwenti/ noun [uncountable]
a type of cricket competition in England in which county teams play against each other in short matches of only twenty overs for each side

[TahlilGaran] Dictionary of Contemporary English ▲