The original meaning of a doodad is a fancy ornament. It has a specific meaning if you watch home improvement shows. However, nowadays it has become a name for something you think does not have a name to it. Synonymous with gadget, gizmo, dohickey etc.

haha it's when you can't remember or don't know the name for something, like the television remote control or a dongle for your pc - where's the doodad?? Haha good question :D

The watchamacallit

"Thingymibob"

Thanks for the answers! :)