The most common and most likely answer to this crossword clue is the 4 letter word KISS
K
I
S
S
More clues leading to the result KISS
- Peck: his last is first in sequence
- Light touch in work is splendid
- Light touch from one X represents
- Part of back is supporting neck
- Veil of doom almost engulfing society
- Gentle touch of some gracious Sikh in retirement
- Collide briefly with runners when cycling
- Plonker from Stanislavski’s school
- Peck travels down piste back to front
- Rick is severe, covering neck
Buddy explains!

The straight part
We know that "X" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case x = kiss.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 KISS mean?
KISS verb- To touch with the lips or press the lips against, usually to show love or affection or passion, or as part of a greeting.
- To (cause to) touch lightly or slightly; to come into contact.
- Of two or more people, to touch each other's lips together, usually to express love or affection or passion.
- To treat with fondness.
- A touch with the lips, usually to express love or affection, or as a greeting.
- An 'X' mark placed at the end of a letter or other type of message.
- A type of filled chocolate candy, shaped as if someone had kissed the top. See Hershey's Kisses.