doohickey
doo-hick-ey
noun
An informal term for a small, unnamed, or forgotten mechanical device or gadget.
"Could you hand me that little doohickey?"
Thesaurus
Synonyms: thingumajig, gizmo, whatchamacallit, whatsis, thingummy, widget, dojigger, whatchamacallum, thingamabob, doodad, gubbins, thingumabob