thingummy

(noun) something unspecified whose name is either forgotten or not known. Synonyms: doodad, doohickey, doojigger, gimmick, gizmo, gismo, gubbins, thingamabob, thingumabob, thingmabob, thingamajig, thingumajig, thingmajig, whatchamacallit, whatchamacallum, whatsis, widget. Examples: "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."