The act of pretending that what is imaginary is real.

imaginary; conjured in someone's imagination, especially when imagined by a child

(religion) Any of those who separated from the official Russian Orthodox Church after 1666 as a protest against church reforms introduced by Patriarch Nikon between 1652 and 1666. They continue liturgical practices which predate the reforms.

(rare) Someone who hides their belief.

plural of make believe

A strict follower of a doctrine. / One who believes dogmatically in something regardless of evidence or even conclusive proof that the thing is false or was staged; one who has true-believer syndrome.

present participle of make believe

A phenomenon in which witnesses to a staged event continue to believe in its authenticity even after it has been debunked.

(idiomatic) An emphatic form of believe me: you (the subject) had better believe me (the speaker).

(idiomatic, chiefly in the negative) To believe that something which one directly sees is truly the case.