RichThesaurus
thingamajiggy
vs
whatchacallit
thingamajiggy
noun
A thingy; something whose name cannot be recalled.
whatchacallit
noun
a whatchamacallit
How often have the words
thingamajiggy
and
whatchacallit
occurred in a corpus of books?
(source:
Google Ngram Viewer
)