ADU ADU /ˌeɪ diː ˈjuː/

noun

1. [ N. American] A self-contained apartment, cottage, or small residential unit located on a property that has a separate main house  ( accessory dwelling unit [ N. American] , ADU [ N. American] , casita [ N. American] )
   a self-contained apartment, cottage, or small residential unit located on a property that has a separate main house