Simple Definition of whatchamacallit
: something whose name you have forgotten or do not know
Full Definition of whatchamacallit
Examples of whatchamacallit
I can't find the whatchamacallit that holds the door open.
<I need one of those whatchamacallits to connect the two patch cords.>
Origin of whatchamacallit
alteration of what you may call it
First Known Use: 1928
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