doo ‧ dah /ˈduːdɑː/ BrE AmE British English , doo‧dad /ˈduːdæd/ American English noun [countable] informal
[ Date: 1900-2000 ; Origin: Probably from the meaningless word dooda in the song Camptown Races ]
a small object whose name you have forgotten or do not know:
Where’s the doodah to turn off the TV?