A small gadget, object, or contraption whose name is unknown, forgotten, or unnecessary to specify; a trinket or gizmo.
Of uncertain origin, possibly from reduplication (dood-) combined with '-ad.' The term became popular in American English in the 1920s-1930s for unnamed mechanical devices.
The fact that 'doodad' doesn't have a clear origin shows how useful placeholder words become—they get used so much we stop caring where they came from and just use them naturally!
Complete word intelligence in one call. Free tier — 50 lookups/day.