The most common and most likely answer to this crossword clue is the 6 letter word ENAMOR
E
N
A
M
O
R
More clues leading to the result ENAMOR
Buddy explains!

The straight part
We know that "Yankee charm?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case yankee charm? = enamor.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 ENAMOR mean?
ENAMOR verb- (mostly in the passive, followed by "of" or "with") To cause to be in love.
- (mostly in the passive) To captivate.