not be whistling Dixie

not be whistling Dixie

AMERICAN
If someone is not whistling Dixie, they are being honest or realistic and should not be ignored. `Is that a threat?' — `I'm not just whistling Dixie.' He was not whistling Dixie last month when he told financial analysts that the firm is as competitive as ever. Note: Dixie was the name given to the region of the southern and eastern United States which formed the Confederate side in the Civil War. The area gave its name to several songs which were popular as Confederate war songs.
See also: Dixie, not, whistle