make-believe

The quality or act of pretending; acting as if something is true when in fact one knows it is not.

Come on, come on, I go up and down / I like this curious feeling / I know, I see, it's like make believe / Cover your ears so you can hear what I'm saying

The condition of pretending or imagining that things are better than they really are.

Something imaginary.

‘You ought to be ashamed of yourself, Marjorie Lindon, to even think such nonsense. Are you all nerves and morbid imaginings,—you who have prided yourself on being so strong-minded! A pretty sort you are to do battle for anyone.—Why, they’re only make-believes!’

Imaginary; not real; pretend.

He called himself Lord So-and-So, even had his family crest on the wall, but it was all totally make-believe.