The most common and most likely answer to this crossword clue is the 11 letter word PREPOSITION
P
R
E
P
O
S
I
T
I
O
N
Buddy explains!
The straight part
We know that "This could be down or across" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case this could be down or across = preposition.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 PREPOSITION mean?
PREPOSITION noun- (grammar, strict sense) Any of a class of non-inflecting words typically employed to connect a following noun or a pronoun, in an adjectival or adverbial sense, with some other word: a particle used with a noun or pronoun (in English always in the objective case) to make a phrase limiting some other word.
- A proposition; an exposition; a discourse.
- To place in a location before some other event occurs.