whatsit
/ˈhwɒtsɪt/noun
- informal a person or thing whose name one cannot recall, does not know, or does not wish to specify〈非正式〉某某人; 某某玩意儿：
"Let's say two o'clock on the whatsit of May?"
“那我们就定在五月某一天的两点钟？”
he's a right old interfering whatsit.
他是个十足的爱管闲事的老家伙。