The most common and most likely answer to this crossword clue is the 3 letter word TEX
T
E
X
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 TEX mean?
TEX noun- A milligram per meter, a unit of linear mass density for thread or fiber.