Make Believe Meaning

(idiomatic) To pretend or imagine.

Example:   Let's build a fort out of chairs and blankets and make believe we are pirates.
1927, Oscar Hammerstein II, Show Boat
  Only make believe I love you, / Only make believe that you love me. / Others find peace of mind in pretending, / Couldn’t you? / Couldn’t I? / Couldn’t we? / Make believe our lips are blending / In a phantom kiss, or two, or three. / Might as well make believe I love you, / For to tell the truth I do.