whatchamacallit
/ˈwɒtʃəməˌkɔːlɪt/noun
RareNot in standard dictionaries
1
A metasyntactic term used for any object whose actual name the speaker does not know or cannot remember; a doodad, gizmo, thingamajig, thingy.
Thesaurus
#colloquial
A metasyntactic term used for any object whose actual name the speaker does not know or cannot remember; a doodad, gizmo, thingamajig, thingy.