[noun] [C] [informal] - any object or person whose name you have temporarily forgotten or do not know or do not want to sayWhere's the whatsit that you change channels with?You'd better tell whatsit - what's his name - the guy in charge of stationery.She kicked him in the whatsits.
WHATSIT
Meaning of WHATSIT in English
Cambridge English vocab. Кембриджский английский словарь. 2012