whistle Dixie engage in unrealistic fantasies; waste your time. US
☞ Dixie as an informal name for the Southern states of the USA probably comes from the Mason-Dixon line, the boundary between Maryland and Pennsylvania established in the 1760s by Charles Mason and Jeremiah Dixon and taken as the northern limit of the slave-owning states. The marching song 'Dixie' (in full 'Dixie's Land') (1859) was popular with Confederate soldiers in the American Civil War.
2001New York Times These guys are just whistling Dixie …They're ignoring the basic issues that everyone's been pointing out to them for a decade.