The most common and most likely answer to this crossword clue is the 2 plus 3 plus 5 letter word IN ANY EVENT
I've seen this crossword clue in The Sunday Telegraph
I
N
A
N
Y
E
V
E
N
T
More clues leading to the result IN ANY EVENT
- Popular, a New York fixture, whatever happens
- Where certain marathon runners are, no matter what?
- Yankee puts on silly voice, regardless of what happens
- Whatever happens, heartless nurse still stops it
- Arising from innate envy regardless of the circumstances
- Where athletes randomly entered, no matter what?
- An all-rounder’s chance is here, no matter what happens
- How an all-round athlete competes whatever happens
- No matter what happens, it’s applying to the whole athletics meeting?
- How one might describe a decathlete’s skill no matter what?
Buddy explains!

The straight part
We know that "no matter what?" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case no matter what? = in any event.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.