The most common and most likely answer to this crossword clue is the 3 letter word ELM
I've seen this crossword clue in The Times
E
L
M
More clues leading to the result ELM
Buddy explains!

The straight part
We know that "wood" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case wood = elm.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 ELM mean?
ELM noun- A tree of the genus Ulmus of the family Ulmaceae, large deciduous trees with alternate stipulate leaves and small apetalous flowers.
- (usually attributive) Wood from an elm tree.