gismo - noun

something unspecified whose name is either forgotten or not known

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

gismo - thesaurus

appliance   contraption   contrivance   convenience   doodad   doohickey   doojigger   gadget   gimmick   gizmo   gubbins   thingamabob   thingamajig   thingmabob   thingmajig   thingumabob   thingumajig   thingummy   whatchamacallit   whatchamacallum   whatsis   widget