The most common and most likely answer to this crossword clue is the 3 letter word NAY
N
A
Y
More clues leading to the result NAY
Buddy explains!

The straight part
We know that "No" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case no = nay.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 NAY mean?
NAY noun- A vote against.
- A person who voted against.
- A denial; a refusal. https//books.google.com/books?id=uysQzJy9IwMC&pg=PA818&dq=%22word+nay+a+denial+refusal%22&hl=en&sa=X&ved=0ahUKEwij_5CHi-3cAhWJ2FMKHWjCDdMQ6AEIJzAA#v=onepage&q=%22word%20nay%20a%20denial%20refusal%22&f=false
- To refuse.
- Nary.
- No.
- Introducing a statement, without direct negation.
- Or rather, or should I say; moreover (introducing a stronger and more appropriate expression than the preceding one).
- No.