thingamajig - noun

something unspecified whose name is either forgotten or not known

thingamajig - thesaurus

doodad   doohickey   doojigger   gimmick   gismo   gizmo   gubbins   thingamabob   thingmabob   thingmajig   thingumabob   thingumajig   thingummy   whatchamacallit   whatchamacallum   whatsis   widget