thingummy

Noun

Meaning

Synonym of thingy: something one cannot remember the name of, or is unable to or does not care to specify precisely.

Synonym of whatshisname: someone one cannot remember the name of.

Source: en.wiktionary.org

hickey gizmo jigger instrument artifact utensil gimmick contraption whatnot gadget doohickey

Work, the what's-its-name of the thingummy and the thing-um-a-bob of the what d'you-call-it. P. G. Wodehouse