To say anything. In S.E. Missouri, to talk turkey, is to talk seriously: Dialect Notes, ii. 333 (1903).
1851. [He] wont get a chance to say turkey to a good-lookin gall to-day!J. J. Hooper, Adventures of Captain Simon Suggs, &c., p. 122.
1909. (Alabama.) She never said pea-turkey to me about it.Dialect Notes, iii. 356. (Italics in the original.)