The most common and most likely answer to this crossword clue is the 7 letter word WHEEDLE
I've seen this crossword clue in The Guardian
W
H
E
E
D
L
E
More clues leading to the result WHEEDLE
- Win over the French added to women's respect
- Coax husband at last into circle with relative at the end
- Flatter, like vehicles with raised base
- We led; he prepared to sweet-talk
- Cajole chap into married life that’s hollow
- Win over the French follows mini-defeat initially around the end of March
- Coax daughter in revolution to end game
- Coax The Hindu to entertain His Excellency and journalist
- Cajole important person having below-average grade at end of June
- I'm excited, finally: Alfred Russel Wallace to attempt charm
Buddy explains!

The straight part
We know that "sweet-talk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sweet-talk = wheedle.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does WHEEDLE mean?
WHEEDLE noun- A coaxing person.
- To cajole or attempt to persuade by flattery.
- To obtain by flattery, guile, or trickery.