the number 20:
a small village twenty miles from Nairobi
I'm nearly twenty (=20 years old).
2TMC [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.
to be aged between 20 and 29
She was in her early twenties when I met her.
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
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).