The most common and most likely answer to this crossword clue is the 5 letter word SMASH
I've seen this crossword clue in The Daily Telegraph
S
M
A
S
H
More clues leading to the result SMASH
- Southern potato when processed is a hit
- Tennis shot Monsieur features in frame
- Hit band pocketing millions
- Accident involving veg in first half of meal
- Small potatoes!? A tremendous success!
- Situated at the front, film is a hit
- Second film from TV series is overwhelming success
- Band receiving money for hit
- Male wearing belt across shoulder for collision
- Second TV series of yesteryear, a big hit
Buddy explains!

The straight part
We know that "break" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case break = smash.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 SMASH mean?
SMASH noun- The sound of a violent impact; a violent striking together.
- A traffic collision.
- Something very successful or popular (as music, food, fashion, etc); a hit.
- A very hard overhead shot hit sharply downward.
- A bankruptcy.
- A kind of julep cocktail containing chunks of fresh fruit that can be eaten after finishing the drink.
- To break (something brittle) violently.
- To be destroyed by being smashed.
- To hit extremely hard.
- To ruin completely and suddenly.
- To defeat overwhelmingly; to gain a comprehensive success.
- To deform through continuous pressure.
- To have sexual intercourse with.