not (just) whistling Dixie
slang Having a realistic or honest view of something, as opposed to an overly optimistic one. "Dixie" was a song popular among Confederate soldiers during the US Civil War and became associated with continuing to hope for the success of a lost cause. It sounds like they really are going to give everyone a raise. You weren't just whistling Dixie, Bob!
not just whistling Dixie
Rur. not talking nonsense. (Alludes to a song titled "Dixie.") Man, you are right! You're not just whistling Dixie. When you say she is wrong, you're not just whistling Dixie.
not just whistling Dixie
(...ˈdɪksi) tv. not talking nonsense. (Folksy. Refers to a song titled Dixie.) Man, you are right! You’re not just whistling Dixie.