The most common and most likely answer to this crossword clue is the 4 letter word AMOK
I've seen this crossword clue in The Guardian
A
M
O
K
More clues leading to the result AMOK
- A practice test taken orally with no control?
- In the morning and certainly berserk
- Brief reassuring message I’d send in a frenzy
- Terse report from survivor is out of control
- Wild morning, fine later
- Wildly providing brief message that there’s nothing to worry about?
- A donkey, virtually wild
- Fine start to day, before losing control
- Brief, reassuring text sent in a state of frenzy
- PM’s predecessor certainly out of control
Buddy explains!

The straight part
We know that "out of control" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case out of control = amok.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.