1. a device or control that is very useful for a particular job

    Synonym: appliancecontraptioncontrivanceconveniencegadgetgizmogismo

2. something unspecified whose name is either forgotten or not known

    e.g. she eased the ball-shaped doodad back into its socket
           there may be some great new gizmo around the corner that you will want to use

    Synonym: doodaddoohickeydoojiggergimmickgizmogismogubbinsthingamabobthingumabobthingmabobthingamajigthingumajigthingmajigthingummywhatchamacallitwhatchamacallumwhatsis