Something unspecified whose name is either forgotten or not known
Doodad
Doohickey
Doojigger
Gimmick
Gismo
Gizmo
Gubbins
Thingamabob
Thingamajig
Thingmabob
Thingmajig
Thingumabob
Thingumajig
Thingummy
Whatchamacallit
Whatsis
Widget
Stuff