The story
Univerbation and contraction of what you may call it. United States, 20th century (recorded in 1921).
Etymology from Wiktionary, CC BY-SA 4.0.
whatchamacallit
what·cha·ma·call·itToday it means: A metasyntactic term used for any object whose actual name the speaker does not know or cannot remember; a doodad, gizmo, thingamajig, thingy. Full definition →