be whistling Dixie

be whistling Dixie

slang To have an unrealistic, usually overly optimistic, view of something. "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. Primarily heard in US. You're whistling Dixie if you think we're making the playoffs this year.
See also: Dixie, whistle
References in periodicals archive ?
You'll be whistling Dixie when you sink your teeth into a spice cake topped with meringue, a Southern specialty.