Longman Dictionary of Contemporary English
Douglas Harper's Etymology Dictionary
Sweet-talk, 1935, from noun phrase; see sweet (adj.) + talk (n.). Earliest usages seem to refer to conversation between black and white in segregated U.S.\n\n"I ain' gonna stay heah no longah. Don' nevah keer, ef I do git cotched
--or die. Tha's bettah than to stay heah an' listen to Maw Haney sweet-talk the white folks, whilst they drives us clean to the grave. ..."
["The Crisis," July 1935]
\nLatin had suaviloquens, literally "sweet-spoken."Wiktionary
vb. 1 To flatter 2 To persuade using flattery
WordNet
Usage examples of "sweet-talk".
Mawbo tried to coax a higher offer by sweet-talking the Kurtzen and taunting the woman, then finally gave up and pointed into the crowd where Sligh was presumably standing.
How could I have been preaching on your private business when I was sweet-talking a voudou queen?
Speech making, when you were supposed to be sweet-talking a voudou queen.
Most of the time he could sweet-talk Cherelle into doing it for him, along with the rest of the cleaning.
Perhaps you have returned to sweet-talk your wife and then intend to indulge your addiction to traveling again, rejoining Madame Bellaire at some point on the globe.
When we turned the bath into a chem lab the girls did make unfriendly comments but when Dad put his foot down, they sweet-talked him into picking it up again and after that they hung their laundry somewhere else, and later Mum stood between us and the house manager when we poured acid down the drain and did the plumbing no good.
He sweet-talked her away from her friends before they all hurried back to the hostel and their prebooked cots.
He persuaded a tool pusher with his own rig to join him, and sweet-talked a bank into taking the farm-in rights against a loan.