Prefix with "Out"

whatsit /ˈwɒtsɪt/ (n):

# (especially British English, informal) ​used when you cannot think of the word or name you want, or do not want to use a particular word.

I've got to make a whatsit for the party. That's it - a flan.

whatshisname /ˈwɒtsɪzneɪm/ (n):

# (also especially disapproving whatshisface /ˈwɒtsɪzfeɪs/) [singular] (informal) ​used to refer to a man whose name you cannot remember, do not know or do not wish to use.

She married whatshisname at number 77.

That's old whatshisface who used to play for Arsenal.

whatshername /ˈwɒtsɜːneɪm/ (n):

# (also especially disapproving whatsherface /ˈwɒtsɜːfeɪs/) [singular] (informal) ​used to refer to a woman whose name you cannot remember, do not know or do not wish to use.

He's coming for the weekend and he's bringing whatshername.

whatsoever /ˌwɒtsəʊˈevə(r)/ (adv):

# no, nothing, none, etc. whatsoever not at all; not of any kind.

They received no help whatsoever.

"Is there any doubt about it?" - "None whatsoever."