A thingamabob, a placeholder word for any unknown or nonspecific object.
Exclamation indicating a successful outcome or sudden realization.
Exclamation acknowledging a witty remark.
Exclamation indicating a successful trick or prank.
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.