twenty twenty /ˈtwɛnti/

adjective

1. () Denoting a quantity consisting of 20 items or units  ( xx , twenty , 20 )
   denoting a quantity consisting of 20 items or units
     She turned twenty years old and celebrated with friends.
   She turned twenty years old and celebrated with friends.
   

noun

1. () The cardinal number that is the sum of nineteen and one  ( XX , twenty , 20 )
   the cardinal number that is the sum of nineteen and one
    I have twenty dollars to spend at the mall
   I have twenty dollars to spend at the mall
   
2. A United States bill worth 20 dollars  ( twenty , twenty dollar bill )
   a United States bill worth 20 dollars