1. a small object or gadget whose name the speaker cannot or does not wish to recall
Usage: informal; also spelled doodad
2. a decorative or ornamental detail or flourish
Usage: informal

Examples

• I need to find that little doodah that holds the shelf up.
• The car has some kind of doodah on the dashboard I've never figured out.
• She added a fancy doodah to the corner of the design.
• Pass me that doodah over there—the one next to the lamp.
• The instructions mention a small plastic doodah that comes in the box.