The most common and most likely answer to this crossword clue is the 3 plus 4 plus 2 plus 5 letter word YOU MARK MY WORDS
Y
O
U
M
A
R
K
M
Y
W
O
R
D
S
Buddy explains!
The straight part
We know that "Note" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case note = you mark my words.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.