Something unspecified whose name is either forgotten or not known.  Synonyms: doodad, doohickey, doojigger, gimmick, gismo, gizmo, gubbins, thingamabob, thingmabob, thingmajig, thingumabob, thingumajig, thingummy, whatchamacallit, whatchamacallum, whatsis, widget.  "There may be some great new gizmo around the corner that you will want to use"