The most common and most likely answer to this crossword clue is the 8 letter word NOTCHING
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Buddy explains!

The straight part
We know that "making marks on wood" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case making marks on wood = notching.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 NOTCHING mean?
NOTCHING verb- To cut a notch in (something).
- To record (a score or similar) by making notches on something.
- To join by means of notches.
- To achieve (something); to add to one's score or record of successes.
- To fit (an arrow) to a bow by means of the notch cut at the end of the arrow; to nock.
- A notched mark or pattern.
- A method of joining framing-timbers, by halving, scarfing, or caulking.