The most common and most likely answer to this crossword clue is the 6 letter word GLUING
I've seen this crossword clue in Independent
G
L
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Buddy explains!
The straight part
We know that "Sticking" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sticking = gluing.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 GLUING mean?
GLUING verb- To join or attach something using glue.
- To cause something to adhere closely to; to follow attentively.
- The act of attaching something with glue.
- A connection between the edges of two planes, or between the points at the ends of two lines.