twen·ty 
/ˈtwɛnti/ noun
plural twen·ties /ˈtwɛnti/ noun 1 [count] : the number 20 2 [count] : the 20th in a set or series
▪ item/question twenty 3 twenties [plural] a : the numbers ranging from 20 to 29
▪ Tomorrow the temperature will be in the low twenties.
b : a set of years ending in digits ranging from 20 to 29
▪ She's in her twenties. ▪ the gangsters of the twenties [=of the 1920s] 4 [count] a US : a twenty-dollar bill
▪ All I have is a twenty.
b Brit : a twenty-pound note
▪ item/question twenty
▪ Tomorrow the temperature will be in the low twenties.
b : a set of years ending in digits ranging from 20 to 29
▪ She's in her twenties. ▪ the gangsters of the twenties [=of the 1920s]
▪ All I have is a twenty.
b Brit : a twenty-pound note
— twen·ti·eth /ˈtwɛntijəθ/ noun, plural twen·ti·eths [count]
▪ What are you doing on the twentieth? [=the twentieth day of the month] ▪ a twentieth of the population
/ˈtwɛntijəθ/ noun, plural twen·ti·eths [count] ▪ What are you doing on the twentieth? [=the twentieth day of the month] ▪ a twentieth of the population
— twentieth adjective
▪ their twentieth anniversary
▪ their twentieth anniversary
— twenty adjective
▪ It was a twenty-hour flight. ▪ twenty days later
▪ It was a twenty-hour flight. ▪ twenty days later
— twenty pronoun
▪ Only twenty showed up for the review session. ▪ We spent forty dollars and had twenty left.
▪ Only twenty showed up for the review session. ▪ We spent forty dollars and had twenty left.
