The most common and most likely answer to this crossword clue is the 3 letter word ZEN
I've seen this crossword clue in The Times
Z
E
N
Buddy explains!
The straight part
We know that "form of Buddhism" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case form of buddhism = zen.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 ZEN mean?
ZEN noun- A denomination of Buddhism.
- Profound meditation within that denomination of Buddhism.
- An approach to an activity, skill, or subject that emphasizes simplicity and intuition rather than conventional thinking or fixation on goals.
- Pertaining to this denomination of Buddhism.
- Enlightened, unburdened and free of worries; chill, extremely relaxed and collected.