The most common and most likely answer to this crossword clue is the 7 letter word KISSING
I've seen this crossword clue in The Daily Telegraph
K
I
S
S
I
N
G
Buddy explains!

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 KISSING mean?
KISSING 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.
- That kisses.
- Just touching.
- The act of giving a kiss.